| 1. |
- Kangas, T., et al.
(författare)
-
Supernova 2013fc in a circumnuclear ring of a luminous infrared galaxy : the big brother of SN 1998S
- 2016
-
Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 456:1, s. 323-346
-
Tidskriftsartikel (refereegranskat)abstract
- We present photometric and spectroscopic observations of SN 2013fc, a bright type II supernova (SN) in a circumnuclear star-forming ring in the luminous infrared galaxy ESO 154-G010, observed as part of the Public ESO Spectroscopic Survey of Transient Objects. SN 2013fc is both photometrically and spectroscopically similar to the well-studied type IIn SN 1998S and to the bright type II-L SN 1979C. It exhibits an initial linear decline, followed by a short plateau phase and a tail phase with a decline too fast for Co-56 decay with full. gamma-ray trapping. Initially, the spectrum was blue and featureless. Later on, a strong broad (similar to 8000 km s(-1)) H alpha emission profile became prominent. We apply a STARLIGHT stellar population model fit to the SN location (observed when the SN had faded) to estimate a high extinction of A(V) = 2.9 +/- 0.2 mag and an age of 10(+ 3) (- 2) Myr for the underlying cluster. We compare the SN to SNe 1998S and 1979C and discuss its possible progenitor star considering the similarities to these events. With a peak brightness of B = - 20.46 +/- 0.21 mag, SN 2013fc is 0.9 mag brighter than SN 1998S and of comparable brightness to SN 1979C. We suggest that SN 2013fc was consistent with a massive red supergiant (RSG) progenitor. Recent mass loss probably due to a strong RSG wind created the circumstellar matter illuminated through its interaction with the SN ejecta. We also observe a near- infrared excess, possibly due to newly condensed dust.
|
|
| 2. |
- Melandri, A., et al.
(författare)
-
GRB171010A/SN 2017htp : a GRB-SN at z=0.33
- 2019
-
Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 490:4, s. 5366-5374
-
Tidskriftsartikel (refereegranskat)abstract
- The number of supernovae known to be connected with long-duration gamma-ray bursts (GRBs) is increasing and the link between these events is no longer exclusively found at low redshift (z less than or similar to 0.3) but is well established also at larger distances. We present a new case of such a liaison at z = 0.33 between GRB171010A and SN 2017htp. It is the second closest GRB with an associated supernova of only three events detected by Fermi-LAT. The supernova is one of the few higher redshift cases where spectroscopic observations were possible and shows spectral similarities with the well-studied SN 1998bw, having produced a similar Ni mass (M-Ni = 0.33 +/- 0.02 M-circle dot) with slightly lower ejected mass (M-ej = 4.1 +/- 0.7 M-circle dot) and kinetic energy (E-K = 8.1 +/- 2.5 x 10(51) erg). The host-galaxy is bigger in size than typical GRB host galaxies, but the analysis of the region hosting the GRB revealed spectral properties typically observed in GRB hosts and showed that the progenitor of this event was located in a very bright H II region of its face-on host galaxy, at a projected distance of similar to 10 kpc from its galactic centre. The star-formation rate (SFRGRB similar to 0.2 M-circle dot yr(-1)) and metallicity (12 + log(O/H) similar to 8.15 +/- 0.10) of the GRB star-forming region are consistent with those of the host galaxies of previously studied GRB-SN systems.
|
|
| 3. |
- Mattila, S., et al.
(författare)
-
A dust-enshrouded tidal disruption event with a resolved radio jet in a galaxy merger
- 2018
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 361:6401, s. 482-485
-
Tidskriftsartikel (refereegranskat)abstract
- Tidal disruption events (TDEs) are transient flares produced when a star is ripped apart by the gravitational field of a supermassive black hole (SMBH). We have observed a transient source in the western nucleus of the merging galaxy pair Arp 299 that radiated >1.5 × 1052erg at infrared and radio wavelengths but was not luminous at optical or x-ray wavelengths. We interpret this as a TDE with much of its emission reradiated at infrared wavelengths by dust. Efficient reprocessing by dense gas and dust may explain the difference between theoretical predictions and observed luminosities of TDEs. The radio observations resolve an expanding and decelerating jet, probing the jet formation and evolution around a SMBH.
|
|
| 4. |
- Iverson, G. L., et al.
(författare)
-
Serum Neurofilament Light Is Elevated Differentially in Older Adults with Uncomplicated Mild Traumatic Brain Injuries
- 2019
-
Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 36:16
-
Tidskriftsartikel (refereegranskat)abstract
- Neurofilament light (NF-L) might have diagnostic and prognostic potential as a blood biomarker for mild traumatic brain injury (mTBI). However, elevated NF-L is associated with several neurological disorders associated with older age, which could confound its usefulness as a traumatic brain injury biomarker. We examined whether NF-L is elevated differentially following uncomplicated mTBI in older adults with pre-injury neurological disorders. In a case-control study, a sample of 118 adults (mean age = 62.3 years, standard deviation [SD] = 22.5, range = 18-100; 52.5% women) presenting to the emergency department (ED) with an uncomplicated mTBI were enrolled. All participants underwent head computed tomography in the ED and showed no macroscopic evidence of injury. The mean time between injury and blood sampling was 8.3 h (median [Md] = 3.5; SD = 13.5; interquartile range [IQR] = 1.9-6.0, range = 0.8-67.4, and 90% collected within 19 h). A sample of 40 orthopedically-injured trauma control subjects recruited from a second ED also were examined. Serum NF-L levels were measured and analyzed using Human Neurology 4-Plex A assay on a HD-1 Single Molecule Array (Simoa) instrument. A high correlation was found between age and NF-L levels in the total mTBI sample (r = 0.80), within the subgroups without pre-injury neurological diseases (r = 0.76) and with pre-injury neurological diseases (r = 0.68), and in the trauma control subjects (r = 0.76). Those with mTBIs and pre-injury neurological conditions had higher NF-L levels than those with no pre-injury neurological conditions (p < 0.001, Cohen's d = 1.01). Older age and pre-injury neurological diseases are associated with elevated serum NF-L levels in patients with head trauma and in orthopedically-injured control subjects.
|
|
| 5. |
- Morris, Simon, et al.
(författare)
-
The ELT-MOS (MOSAIC) : towards the construction phase
- 2018
-
Ingår i: GROUND-BASED AND AIRBORNE INSTRUMENTATION FOR ASTRONOMY VII. - : SPIE-INT SOC OPTICAL ENGINEERING. - 9781510619586 ; 10702
-
Konferensbidrag (refereegranskat)abstract
- When combined with the huge collecting area of the ELT, MOSAIC will be the most effective and flexible Multi-Object Spectrograph (MOS) facility in the world, having both a high multiplex and a multi-Integral Field Unit (Multi-IFU) capability. It will be the fastest way to spectroscopically follow-up the faintest sources, probing the reionisation epoch, as well as evaluating the evolution of the dwarf mass function over most of the age of the Universe. MOSAIC will be world-leading in generating an inventory of both the dark matter (from realistic rotation curves with MOAO fed NIR IFUs) and the cool to warm-hot gas phases in z=3.5 galactic haloes (with visible wavelenth IFUs). Galactic archaeology and the first massive black holes are additional targets for which MOSAIC will also be revolutionary. MOAO and accurate sky subtraction with fibres have now been demonstrated on sky, removing all low Technical Readiness Level (TRL) items from the instrument. A prompt implementation of MOSAIC is feasible, and indeed could increase the robustness and reduce risk on the ELT, since it does not require diffraction limited adaptive optics performance. Science programmes and survey strategies are currently being investigated by the Consortium, which is also hoping to welcome a few new partners in the next two years.
|
|
| 6. |
- Aalto, Susanne, 1964, et al.
(författare)
-
ALMA resolves the remarkable molecular jet and rotating wind in the extremely radio-quiet galaxy NGC 1377
- 2020
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 640
-
Tidskriftsartikel (refereegranskat)abstract
- Submillimetre and millimetre line and continuum observations are important in probing the morphology, column density, and dynamics of the molecular gas and dust around obscured active galactic nuclei (AGNs) and their mechanical feedback. With very high-resolution (0.'' 02x0.'' 03 (2x3 pc)) ALMA 345 GHz observations of CO 3-2, HCO+ 4-3, vibrationally excited HCN 4-3 nu (2)=1f, and continuum we have studied the remarkable, extremely radio-quiet, molecular jet and wind of the lenticular galaxy NGC 1377. The outflow structure is resolved, revealing a 150 pc long, clumpy, high-velocity (similar to 600 km s(-1)), collimated molecular jet where the molecular emission is emerging from the spine of the jet with an average diameter of 3-7 pc. The jet widens to 10-15 pc about 25 pc from the centre, which is possibly due to jet-wind interactions. A narrow-angle (50 degrees -70 degrees), misaligned and rotating molecular wind surrounds the jet, and both are enveloped by a larger-scale CO-emitting structure at near-systemic velocity. The jet and narrow wind have steep radial gas excitation gradients and appear turbulent with high gas dispersion (sigma> 40 km s(-1)). The jet shows velocity reversals that we propose are caused by precession, or more episodic directional changes. We discuss the mechanisms powering the outflow, and we find that an important process for the molecular jet and narrow wind is likely magneto-centrifugal driving. In contrast, the large-scale CO-envelope may be a slow wind, or cocoon that stems from jet-wind interactions. An asymmetric, nuclear r similar to 2 pc dust structure with a high inferred molecular column density N(H-2) similar or equal to 1.8x10(24) cm(-2) is detected in continuum and also shows compact emission from vibrationally excited HCN. The nuclear dust emission is hot (T-d> 180 K) and its luminosity is likely powered by a buried AGN. The lopsided structure appears to be a warped disk, which is responsible for a significant part of the nuclear obscuration and possibly formed as a result of uneven gas inflows. The dynamical mass inside r=1.4 pc is estimated to 9(-3)(+2) x 10(6)M(circle dot) 9 - 3 + 2 x 10 6 M circle dot , implying that the supermassive black hole (SMBH) has a high mass with respect to the stellar velocity dispersion of NGC 1377. We suggest that the SMBH of NGC 1377 is currently in a state of moderate growth, at the end of a more intense phase of accretion and also evolving from a state of more extreme nuclear obscuration. The nuclear growth may be fuelled by low-angular momentum gas inflowing from the gas ejected in the molecular jet and wind. Such a feedback-loop of cyclic outflows and central accretion could explain why there is still a significant reservoir of molecular gas in this ageing, lenticular galaxy. A feedback-loop would be an effective process in growing the nuclear SMBH and thus would constitute an important phase in the evolution of NGC 1377. This also invites new questions as to SMBH growth processes in obscured, dusty galaxies.
|
|
| 7. |
- Aalto, Susanne, 1964, et al.
(författare)
-
Luminous, pc-scale CO 6-5 emission in the obscured nucleus of NGC 1377
- 2017
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 608, s. A22-
-
Tidskriftsartikel (refereegranskat)abstract
- High-resolution submillimeter line and continuum observations are important in probing the morphology, column density, and dynamics of the molecular gas and dust around obscured active galactic nuclei (AGNs). With high-resolution (0'.06 x 0'.05 (6 x 5 pc)) ALMA 690 GHz observations we have found bright (T-B > 80 K) and compact (full width half maximum size (FWHM) size of 10 x 7 pc) CO 6-5 line emission in the nuclear region of the extremely radio-quiet galaxy NGC 1377. The CO 6-5 intensity is partially aligned with the previously discovered jet/outflow of NGC 1377 and is tracing dense (n > 10(4 )cm(-3)) hot molecular gas at the base of the outflow. The velocity structure is complex and shifts across the jet/outflow are discussed in terms of separate overlapping kinematical components or rotation. High-velocity gas (Delta v +/- 145 km s(-1)) is detected inside r
|
|
| 8. |
- Andrén, T., et al.
(författare)
-
The Baltic Sea IODP project
- 2012
-
Ingår i: EGU General Assembly Conference Abstracts. ; , s. 7682-7682
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
|
|
| 9. |
- Hyttinen, O., et al.
(författare)
-
Holocene stratigraphy of the Ångermanälven River estuary, Bothnian Sea
- 2017
-
Ingår i: Geo-Marine Letters. - : Springer. - 0276-0460 .- 1432-1157. ; 37:3, s. 273-288
-
Tidskriftsartikel (refereegranskat)abstract
- This study explores the Holocene depositional succession at the IODP Expedition 347 sites M0061 and M0062 in the vicinity of the Ångermanälven River estuary in the Bothnian Sea sector of the Baltic Sea in northern Scandinavia. Site M0061 is located in a coastal offshore setting (87.9 m water depth), whereas site M0062 is fully estuarine (69.3 m water depth). The dataset comprises acoustic profiles and sediment cores collected in 2007 and late 2013 respectively. Three acoustic units (AUs) were recognized. Lowermost AU1 is interpreted as a poorly to discontinuous stratified glaciofluvial deposit, AU2 as a stratified conformable drape of glaciolacustrine origin, and AU3 as a poorly stratified to stratified mud drift. A strong truncating reflector separates AU2 and AU3. Three lithological units (LUs) were defined in the sediment cores. LU1 consists of glaciofluvial sand and silt gradating into LU2, which consists of glaciolacustrine varves. A sharp contact interpreted as a major unconformity separates LU2 from the overlying LU3 (brackish-water mud). In the basal part of LU3, one debrite (site M0061) or two debrites (site M0062) were recognized. Information yielded from sediment physical properties (magnetic susceptibility, natural gamma ray, dry bulk density), geochemistry (total carbon, total organic carbon, total inorganic carbon and nitrogen), and grain size support the LU division. The depositional succession was formally subdivided into two alloformations: the Utansjö Alloformation and overlying Hemsön Alloformation; the Utansjö Alloformation was further subdivided into two lithostratigraphic formations: the Storfjärden and Åbordsön formations. The Storfjärden (sandy outwash) and Åbordsön (glaciolacustrine rhythmite) formations represent a glacial retreat systems tract, which started at ca. 10.6 kyr BP. Their deposition was mainly controlled by meltwater from the retreating ice margin, glacio-isostatic land uplift and the regressive (glacial) lake level. The Hemsön Alloformation (organic-rich brackish-water mud) represents a period of forced regression, starting possibly at ca. 9.5 kyr BP. At about 7 kyr BP, brackish water reached the study area as a result of the mid-Holocene marine flooding of the Baltic Sea Basin, but the rapid land uplift soon surpassed the associated (Littorina) transgression. Changed near-bottom current patterns, caused by the establishment of a permanent halocline, and the reduced sediment consistency caused by increased organic deposition resulted in a sharp and erosional base of the brackish-water mud. Estuarine processes and salinity stratification at site M0062 started to play a more important role. This study applies a combined allostratigraphic and lithostratigraphic approach over the conventional Baltic Sea stages. This approach makes it more straightforward to study this Baltic Sea deglaciation–postglacial sequence and compare it to other formerly glaciated shallow sea estuaries.
|
|
| 10. |
- Kotilainen, Aarno T., et al.
(författare)
-
Echoes from the Past : A Healthy Baltic Sea Requires More Effort
- 2014
-
Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 43:1, s. 60-68
-
Tidskriftsartikel (refereegranskat)abstract
- Integrated sediment multiproxy studies and modeling were used to reconstruct past changes in the Baltic Sea ecosystem. Results of natural changes over the past 6000 years in the Baltic Sea ecosystem suggest that forecasted climate warming might enhance environmental problems of the Baltic Sea. Integrated modeling and sediment proxy studies reveal increased sea surface temperatures and expanded seafloor anoxia (in deep basins) during earlier natural warm climate phases, such as the Medieval Climate Anomaly. Under future IPCC scenarios of global warming, there is likely no improvement of bottom water conditions in the Baltic Sea. Thus, the measures already designed to produce a healthier Baltic Sea are insufficient in the long term. The interactions between climate change and anthropogenic impacts on the Baltic Sea should be considered in management, implementation of policy strategies in the Baltic Sea environmental issues, and adaptation to future climate change.
|
|
| 11. |
- Virtasalo, Joonas J., et al.
(författare)
-
Pyritic and baritic burrows and microbial filaments in postglacial lacustrine clays in the northern Baltic Sea
- 2010
-
Ingår i: Journal of the Geological Society. - : Geological Society of London. - 0016-7649 .- 2041-479X. ; 167:6, s. 1185-1198
-
Tidskriftsartikel (refereegranskat)abstract
- Holocene postglacial lacustrine clays in the northern Baltic Sea were studied for ichnofossils,petrography, and microscale elemental and 34S/32S composition to understand the impact of benthos-producedorganic matrices on the early diagenesis of sediments. X-radiographs of these clays display intense burrowmottling with discrete Palaeophycus, ‘Mycellia’ and rare Arenicolites. Small burrow-like and irregularlyshaped concretions were separated from these clays. The burrow-like concretions are composed of framboidalpyrite and poorly crystalline FeS2 cement. They formed within worm-produced burrows by the decompositionof mucous coatings on the burrow walls by sulphate reduction. 34SCDT composition of the framboidsindicates saline inflows from the North Sea as the sulphate source. The irregular concretions are microcrystallinepyritic masses that formed in pore spaces with less reactive organic compounds. Their 34SCDT valuesreflect precipitation from the ambient porewater sulphate by sulphate reduction. The burrow-like and irregularconcretions are microcrystalline barite in the lower parts of the clays. ‘Mycellia’ are mineral-replacedfilaments produced by large sulphur-oxidizing bacteria or mycelial fungi. They concentrate in monosulphidebands in the lower substrate levels, but are associated with organic patches upward. This study demonstratesthat substantial amounts of pyrite formed within organic matrices close to the sediment–water interface. Thisdiffers from previous studies that proposed a deeper-burial origin and allochthonous sulphur source.
|
|
| 12. |
- Aalto, Susanne, 1964, et al.
(författare)
-
A precessing molecular jet signaling an obscured, growing supermassive black hole in NGC 1377?
- 2016
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 590, s. Art. no. A73-
-
Tidskriftsartikel (refereegranskat)abstract
- With high resolution (0."25 × 0."18) ALMA CO 3-2 (345 GHz) observations of the nearby (D = 21 Mpc, 1" = 102 pc), extremely radio-quiet galaxy NGC 1377, we have discovered a high-velocity, very collimated nuclear outflow which we interpret as a molecular jet with a projected length of ± 150 pc. The launch region is unresolved and lies inside a radius r 40% of the flux in NGC 1377 and may be a slower, wide-angle molecular outflow which is partially entrained by the molecular jet. We discuss the driving mechanism of the molecular jet and suggest that it is either powered by a (faint) radio jet or by an accretion disk-wind similar to those found towards protostars. It seems unlikely that a massive jet could have been driven out by the current level of nuclear activity which should then have undergone rapid quenching. The light jet would only have expelled 10% of the inner gas and may facilitate nuclear activity instead of suppressing it. The nucleus of NGC 1377 harbours intense embedded activity and we detect emission from vibrationally excited HCN J = 4-3?2 = 1f which is consistent with hot gas and dust. We find large columns of H2 in the centre of NGC 1377 which may be a sign of a high rate of recent gas infall. The dynamical age ofthe molecular jet is short (
|
|
| 13. |
- Brelsford, Craig C., et al.
(författare)
-
Do UV‐A radiation and blue light during growth prime leaves to cope with acute high light in photoreceptor mutants of Arabidopsis thaliana?
- 2019
-
Ingår i: Physiologia Plantarum. - : Blackwell Publishing. - 0031-9317 .- 1399-3054. ; 165:3, s. 537-554
-
Tidskriftsartikel (refereegranskat)abstract
- We studied how plants acclimated to growing conditions that included combinations of blue light (BL) and ultraviolet (UV)‐A radiation, and whether their growing environment affected their photosynthetic capacity during and after a brief period of acute high light (as might happen during an under‐canopy sunfleck). Arabidopsis thaliana Landsberg erecta wild‐type were compared with mutants lacking functional blue light and UV photoreceptors: phototropin 1, cryptochromes (CRY1 and CRY2) and UV RESISTANT LOCUS 8 (uvr8). This was achieved using light‐emitting‐diode (LED) lamps in a controlled environment to create treatments with or without BL, in a split‐plot design with or without UV‐A radiation. We compared the accumulation of phenolic compounds under growth conditions and after exposure to 30 min of high light at the end of the experiment (46 days), and likewise measured the operational efficiency of photosystem II (ϕPSII, a proxy for photosynthetic performance) and dark‐adapted maximum quantum yield (Fv/Fm to assess PSII damage). Our results indicate that cryptochromes are the main photoreceptors regulating phenolic compound accumulation in response to BL and UV‐A radiation, and a lack of functional cryptochromes impairs photosynthetic performance under high light. Our findings also reveal a role for UVR8 in accumulating flavonoids in response to a low UV‐A dose. Interestingly, phototropin 1 partially mediated constitutive accumulation of phenolic compounds in the absence of BL. Low‐irradiance BL and UV‐A did not improve ϕPSII and Fv/Fm upon our acute high‐light treatment; however, CRYs played an important role in ameliorating high‐light stress.
|
|
| 14. |
- Hyttinen, O., et al.
(författare)
-
Deglaciation dynamics of the Fennoscandian Ice Sheet in the Kattegat, the gateway between the North Sea and the Baltic Sea Basin
- 2021
-
Ingår i: Boreas. - : John Wiley & Sons. - 0300-9483 .- 1502-3885. ; 50:2, s. 351-368
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents an age–depth model based on an ultra-high-resolution, 80-m-thick sedimentary succession from a marine continental shelf basin, the Kattegat. This is an area of dynamic deglaciation of the Fennoscandian Ice Sheet during the Late Pleistocene. The Kattegat is also a transitional area between the saline North Sea and the brackish Baltic Sea. As such, it records general development of currents and exchange between these two systems. Data for the succession were provided through the Integrated Ocean Drilling Program Site M0060. The site indicates onset of deglaciation at c. 18 ka BP and relatively continuous sedimentation until 13 ka BP. At this point, sediments record a hiatus until c. 9–7 ka BP. The uppermost sedimentary unit contains redeposited material, but it is estimated to represent only the last c. 9–7 ka BP. The age–depth model is based on 17 select, radiocarbon-dated samples and is integrated with a set of physical and chemical proxies. The integrated records provide novel constraints on the timing of major palaeoenvironmental changes, such as the transition from glaciomarine proximal to glaciomarine distal and marine conditions, and their connections to known major events and processes in the region and the North Atlantic. Depositional evidence specifically documents connections between the Fennoscandian Ice Sheet behaviour and atmospheric and oceanic warming. Glacial retreat may have also depended on topographic factors such as changes in basin width and depth, linked to relative sea level changes and land uplift. The results indicate an early response of the Fennoscandian Ice Sheet to changing climate, and the ice sheet's possible influence on oceanic circulation during the Late Pleistocene deglaciation.
|
|
| 15. |
- Kankare, E., et al.
(författare)
-
Core-collapse supernova subtypes in luminous infrared galaxies
- 2021
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 649
-
Tidskriftsartikel (refereegranskat)abstract
- The fraction of core-collapse supernovae (CCSNe) occurring in the central regions of galaxies is not well constrained at present. This is partly because large-scale transient surveys operate at optical wavelengths, making it challenging to detect transient sources that occur in regions susceptible to high extinction factors. Here we present the discovery and follow-up observations of two CCSNe that occurred in the luminous infrared galaxy (LIRG) NGC 3256. The first, SN 2018ec, was discovered using the ESO HAWK-I /GRAAL adaptive optics seeing enhancer, and was classified as a Type Ic with a host galaxy extinction of AV = 2:1+0:3 0:1 mag. The second, AT 2018cux, was discovered during the course of follow-up observations of SN 2018ec, and is consistent with a subluminous Type IIP classification with an AV = 2:1 +/- 0:4 mag of host extinction. A third CCSN, PSN J10275082 4354034 in NGC 3256, was previously reported in 2014, and we recovered the source in late-time archival Hubble Space Telescope imaging. Based on template light curve fitting, we favour a Type IIn classification for it with modest host galaxy extinction of AV = 0:3+0:4 0:3 mag. We also extend our study with follow-up data of the recent Type IIb SN 2019lqo and Type Ib SN 2020fkb that occurred in the LIRG system Arp 299 with host extinctions of AV = 2:1 +0:1 0 :3 and AV = 0:4 +0:1 0 :2 mag, respectively. Motivated by the above, we inspected, for the first time, a sample of 29 CCSNe located within a projected distance of 2.5 kpc from the host galaxy nuclei in a sample of 16 LIRGs. We find, if star formation within these galaxies is modelled assuming a global starburst episode and normal IMF, that there is evidence of a correlation between the starburst age and the CCSN subtype. We infer that the two subgroups of 14 H-poor (Type IIb /Ib /Ic /Ibn) and 15 H-rich (Type II /IIn) CCSNe have di fferent underlying progenitor age distributions, with the H-poor progenitors being younger at 3 sigma significance. However, we note that the currently available sample sizes of CCSNe and host LIRGs are small, and the statistical comparisons between subgroups do not take into account possible systematic or model errors related to the estimated starburst ages.
|
|
| 16. |
- Kankare, E., et al.
(författare)
-
DISCOVERY OF TWO SUPERNOVAE IN THE NUCLEAR REGIONS OF THE LUMINOUS INFRARED GALAXY IC 883
- 2012
-
Ingår i: Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 744:2
-
Tidskriftsartikel (refereegranskat)abstract
- We report the discovery of two consecutive supernovae (SNe), 2010cu and 2011hi, located at 0 ''.37 (180 pc) and 0 ''.79 (380 pc) projected distance, respectively, from the center of the K-band nucleus of the luminous infrared galaxy (LIRG) IC 883. The SNe were discovered in an ongoing near-infrared K-band search for core-collapse SNe in such galaxies using the ALTAIR/NIRI adaptive optics system with laser guide star at the Gemini-North Telescope. These are thus the closest SNe yet discovered to an LIRG nucleus in optical or near-infrared wavelengths. The near-infrared light curves and colors of both SNe are consistent with core-collapse events. Both SNe seem to suffer from relatively low host galaxy extinction suggesting that regardless of their low projected galactocentric distances, they are not deeply buried in the nuclear regions of the host galaxy.
|
|
| 17. |
|
|
| 18. |
- Kotilainen, Kirsi, et al.
(författare)
-
Business model readiness of start-up driven energy innovations – an empirical review
- 2019
-
Ingår i: 16th International Conference on the European Energy Market (EEM). - : IEEE Computer Society. - 9781728112572
-
Konferensbidrag (refereegranskat)abstract
- When will the start-ups enter the play field of energy innovations in mass? The energy sector has traditionally been a challenging industry to new entrants, especially for smaller firms. Digitalization, decentralization and new renewable energy technologies are enabling also smaller actors to create energy-related innovations. This research focuses on understanding the level of business model readiness of start-ups when commercializing energy innovations. We interviewed start-up companies and provide an analysis of the state of their business models mapped with key challenges that these firms face. Our results show that while most start-ups have a promising value proposition they struggle with other value creation and value capture aspects. Especially building the sales channel that often requires co-operation with energy industry incumbents and finding the right revenue model causes problems to the startups. The challenges the start-ups face also depend on their focus; technology-based start-ups appear to have more obstacles than data-driven start-ups due to longer time needed to mature the products for commercial deployment.
|
|
| 19. |
- Kotilainen, Kirsi, et al.
(författare)
-
Exploring the microfoundations of end-user interests toward co-creating renewable energy technology innovations
- 2019
-
Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 229, s. 203-212
-
Tidskriftsartikel (refereegranskat)abstract
- Energy market transition, which is enabled by new affordable energy technologies and digitalization, opens novel opportunities for developing innovative energy solutions. These new technologies facilitate energy consumers to become local energy prosumers i.e. consumers and producers of energy using renewable energy sources. Hence, a central question for innovating new solutions emerges: how energy consumers and prosumers would engage in co-creating value and novel solutions with industry players? This article explores the microfoundations of energy consumers' and prosumers’ interest to participate in co-creation activities with energy industry actors. Using survey data from five European countries and by applying variance-based structural equation modeling, we find that rewards and personal characteristics influence the interest to engage in co-creation activities. Specifically, the microfoundations of the interest are built upon the need for improvements, the intrinsic rewards, and the personal adopter characteristics. Additionally, we find differing microfoundations of interest for energy consumers and prosumers. We further discuss managerial and theoretical implications of our findings and highlight avenues for future research.
|
|
| 20. |
- Kotilainen, K., et al.
(författare)
-
From energy consumers to prosumers-how do policies influence the transition?
- 2021
-
Ingår i: Electrification. - : Elsevier. - 9780128221433 - 9780128221761 ; , s. 197-215
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Active producer-consumers (prosumers) still number relatively few in most countries, excluding frontrunner countries such as Germany and the USA, where small-scale solar power generation by property-owners has made strong inroads. To unleash their potential for a transition to a more climate-neutral electric energy system, identifying the potential enablers and constraints for the proliferation of prosumption is crucial. Policy mixes have been identified as important enablers for industry transitions. We report a case comparing the similarities and differences among prosumer-related policies in five European countries: Finland, France, Germany, Italy, and Switzerland. We also introduce an empirical case study on how policies in these countries may influence consumer attitudes in favor of small-scale renewable energy production. We conclude the chapter by discussing the best practices and the mix of more precise policy instruments deployable for involving citizens in order to accelerate the electrification of the energy system.
|
|
| 21. |
- Moros, Matthias, et al.
(författare)
-
Towards an event stratigraphy for Baltic Sea sediments deposited since AD 1900 : approaches and challenges
- 2017
-
Ingår i: Boreas. - : Wiley. - 0300-9483 .- 1502-3885. ; 46:1, s. 129-142
-
Tidskriftsartikel (refereegranskat)abstract
- Reconstructions of environmental changes at sub-decadal to decadal resolution based on central Baltic Sea sediments rely on accurate and precise high-resolution sediment depth/age relationships. A model chronology for Baltic Sea sediments is presented here based on established historical records of anthropogenic radionuclides (Cs-137/Am-241/bomb(14)C), polychlorinated biphenyls (PCBs), lead (Pb) and stable lead isotope (Pb-206/207 ratios), and radionuclide Pb-210 and C-14 decay dating methods. Marker horizons consisting of chemical precipitates formed by documented Major Baltic Inflow (MBIs) events and an extended diatom bloom period were also integrated into the model. The main time markers in Baltic Sea sediments that formed during the last 120years were the following: (i) the deepest observation of Pb-210(unsupp.) (marking the Pb-210 dating horizon) and departure of Hg from natural background levels at c.AD 1900; (ii) first detectable presence of PCBs at AD 1935; (iii) radionuclide production (i.e. Am-241) due to nuclear weapons testing between AD 1954 and AD 1975, with a peak in AD 1963; (iv) maximum heavy metal and PCB concentrations in the AD 1960s/1970s; (v) the Chernobyl nuclear accident in AD 1986 as a sharp Cs-137 increase; (vi) exceptionally strong diatom blooms with a massive diatom layer found in the Eastern Gotland Basin in AD 1988-1990; and (vii) characteristic manganese-carbonate layers in the deeper central basins formed by MBIs in AD 1993 and AD 2003. A precise and accurate sediment depth/age relationship can only be achieved in restricted areas of the Baltic Sea where continuous sedimentation has prevailed and there has been limited postdepositional disturbance. We demonstrate that parallel Hg and Cs-137 measurements can be used to assess the quality of sediment sequences for high-resolution environmental reconstructions. We show examples of sediment profiles that conform to the historical record, and examples from Western Baltic Sea areas where it appears to be impossible to establish accurate geochronologies.
|
|
| 22. |
- Mäkinen, Saku J., et al.
(författare)
-
Prosumers’ digital business models for electric vehicles : Exploring microfoundations for a balanced policy approach
- 2019
-
Ingår i: Digital business models. - Cham : Palgrave Macmillan. - 9783319969015 - 9783319969022 ; , s. 227-254
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Mäkinen et al. provide an indispensable view of business model opportunities for electric vehicle (EV) prosumers in the future energy market. The digitalization of energy markets has started a transformation to smart grids where information flows bi-directionally end to end between energy production and consumption. The chapter explores how prosumers can create, deliver, and capture value with EVs in future energy systems. Focusing on prosumers’ digital business models (DBMs), the chapter illustrates the complex interdependencies between various activities and actors needed in the development of an energy system. In addition to demonstrating prosumers’ EV DBMs and the current state of readiness in value creation, delivery, and capture, Mäkinen et al. develop a balanced policy approach that is based on these DBM microfoundations.
|
|
| 23. |
- Puttonen, Irma, et al.
(författare)
-
Distribution and estimated release of sediment phosphorus in the northern Baltic Sea archipelagos
- 2014
-
Ingår i: Estuarine, Coastal and Shelf Science. - : Elsevier BV. - 0272-7714 .- 1096-0015. ; 145, s. 9-21
-
Tidskriftsartikel (refereegranskat)abstract
- Phosphorus contents in the sediments were determined in archipelago areas of the northern Baltic Sea (Svealand in Sweden and Aland, SW Finland and W Uusimaa in Finland) during 2008-2012. Spatial and vertical distribution of phosphorus was studied by analysing sediment samples from 345 stations of different seabed substrate types. A sequential extraction method was applied to evaluate the pool of the potentially mobile phosphorus, i.e., the amount of phosphorus that can be expected to be released from sediments to water with time, and possibly support primary production. In addition, vertical distribution of immobile phosphorus forms in the sediments was used as a tool to assess phosphorus burial. The uppermost 2 cm of sediments were calculated to contain 126,000 tonnes of phosphorus in the study area covering 19,200 km(2) of the seafloor. Subtracting the assumed average background content (i.e. that assumed to be buried) of this total phosphorus content gave an estimation of 31,000-37,000 tonnes of potentially mobile phosphorus at the sediment surface. Redox sensitive iron-bound phosphorus accounts for two thirds of this pool. Compared with the total phosphorus input from the catchment of the entire Baltic Sea 29,000 tonnes in 2009 it can be concluded that the store of phosphorus that can be released with time from the sediments is large, and that internal phosphorus recycling processes thus may play a key role in phosphorus fluxes in the coastal zone. Spreading of hypoxia in the future, as recent modelling and sediment proxy results suggest, is likely to severely deteriorate the water quality, particularly in the archipelago areas where the water exchange is slow.
|
|
| 24. |
- Robson, T. Matthew, et al.
(författare)
-
A perspective on ecologically relevant plant-UV research and its practical application
- 2019
-
Ingår i: Photochemical and Photobiological Sciences. - : Royal Society of Chemistry. - 1474-905X .- 1474-9092. ; 18:5, s. 970-988
-
Tidskriftsartikel (refereegranskat)abstract
- Plants perceive ultraviolet-B (UV-B) radiation through the UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8), and initiate regulatory responses via associated signalling networks, gene expression and metabolic pathways. Various regulatory adaptations to UV-B radiation enable plants to harvest information about fluctuations in UV-B irradiance and spectral composition in natural environments, and to defend themselves against UV-B exposure. Given that UVR8 is present across plant organs and tissues, knowledge of the systemic signalling involved in its activation and function throughout the plant is important for understanding the context of specific responses. Fine-scale understanding of both UV-B irradiance and perception within tissues and cells requires improved application of knowledge about UV-attenuation in leaves and canopies, warranting greater consideration when designing experiments. In this context, reciprocal crosstalk among photoreceptor-induced pathways also needs to be considered, as this appears to produce particularly complex patterns of physiological and morphological response. Through crosstalk, plant responses to UV-B radiation go beyond simply UV-protection or amelioration of damage, but may give cross-protection over a suite of environmental stressors. Overall, there is emerging knowledge showing how information captured by UVR8 is used to regulate molecular and physiological processes, although understanding of upscaling to higher levels of organisation, i.e. organisms, canopies and communities remains poor. Achieving this will require further studies using model plant species beyond Arabidopsis, and that represent a broad range of functional types. More attention should also be given to plants in natural environments in all their complexity, as such studies are needed to acquire an improved understanding of the impact of climate change in the context of plant-UV responses. Furthermore, broadening the scope of experiments into the regulation of plant-UV responses will facilitate the application of UV radiation in commercial plant production. By considering the progress made in plant-UV research, this perspective highlights prescient topics in plant-UV photobiology where future research efforts can profitably be focussed. This perspective also emphasises burgeoning interdisciplinary links that will assist in understanding of UV-B effects across organisational scales and gaps in knowledge that need to be filled so as to achieve an integrated vision of plant responses to UV-radiation.
|
|
| 25. |
- Saari, Ulla A., et al.
(författare)
-
Engaging students in cross-disciplinary research and education—A processual approach to educational development
- 2019
-
Ingår i: Handbook of sustainability science and research. - Cham : Springer. - 9783319630069 - 9783319630076 ; , s. 353-363
-
Bokkapitel (refereegranskat)abstract
- The creation of future sustainable and efficient energy systems requires a cross-disciplinary approach in engineering education. In order for energy-related engineering students to be prepared for real-world situations after their studies, it is important that, while they are still studying, they obtain the basic skills for handling different concepts, theoretical frameworks and solution types created in the various disciplines involved. At the Tampere University of Technology (TUT), a cross-disciplinary team was formed from four different departments in three different faculties to create a platform for research and education purposes on the university campus. The purpose was to coordinate research and provide students with a wider picture and a concrete implementation of the different layers and aspects that need to be taken into account when creating innovative solutions for future digital energy systems. The creation of the platform started from a successful student ideation competition that produced many viable solutions. This paper describes the bottom-up incremental process by which the cross-disciplinary platform was created. The innovative solutions created in the student ideation competition convinced the university organization that the cross-disciplinary collaboration should have a more permanent platform on the university campus, allowing researchers and students to incorporate more sustainability and systemic aspects into their work, and having a positive impact on the sustainable energy consumption on the campus.
|
|
