| 1. |
|
|
| 2. |
|
|
| 3. |
- Burillo, S. G., et al.
(författare)
-
Molecular line emission in NGC 1068 imaged with ALMA : I. An AGN-driven outflow in the dense molecular gas
- 2014
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 567, s. 125-
-
Tidskriftsartikel (refereegranskat)abstract
- Aims. We investigate the fueling and the feedback of star formation and nuclear activity in NGC 1068, a nearby (D = 14 Mpc) Seyfert 2 barred galaxy, by analyzing the distribution and kinematics of the molecular gas in the disk. We aim to understand if and how gas accretion can self-regulate.Methods. We have used the Atacama Large Millimeter Array (ALMA) to map the emission of a set of dense molecular gas (n(H2) ' 1056 cm3) tracers (CO(3-2), CO(6-5), HCN(4-3), HCO+(4-3), and CS(7-6)) and their underlying continuum emission in the central r ∼ 2 kpc of NGC 1068 with spatial resolutions ∼0:3000:500 (∼20-35 pc for the assumed distance of D = 14 Mpc). Results. The sensitivity and spatial resolution of ALMA give an unprecedented detailed view of the distribution and kinematics of the dense molecular gas (n(H2) ≈ 1056cm3) in NGC 1068. Molecular line and dust continuum emissions are detected from a r ∼ 200 pc off-centered circumnuclear disk (CND), from the 2.6 kpc-diameter bar region, and from the r ∼ 1:3 kpc starburst (SB) ring. Most of the emission in HCO+, HCN, and CS stems from the CND. Molecular line ratios show dramatic order-of-magnitude changes inside the CND that are correlated with the UV/X-ray illumination by the active galactic nucleus (AGN), betraying ongoing feedback. We used the dust continuum fluxes measured by ALMA together with NIR/MIR data to constrain the properties of the putative torus using CLUMPY models and found a torus radius of 20+6 10 pc. The Fourier decomposition of the gas velocity field indicates that rotation is perturbed by an inward radial flow in the SB ring and the bar region. However, the gas kinematics from r ∼ 50 pc out to r ∼ 400 pc reveal a massive (Mmol ∼ 2:7+0:9 1:2 × 107 M) outflow in all molecular tracers. The tight correlation between the ionized gas outflow, the radio jet, and the occurrence of outward motions in the disk suggests that the outflow is AGN driven. Conclusions. The molecular outflow is likely launched when the ionization cone of the narrow line region sweeps the nuclear disk. The outflow rate estimated in the CND, dM=dt ∼ 63+21 37 M yr1, is an order of magnitude higher than the star formation rate at these radii, confirming that the outflow is AGN driven. The power of the AGN is able to account for the estimated momentum and kinetic luminosity of the outflow. The CND mass load rate of the CND outflow implies a very short gas depletion timescale of ≤1 Myr. The CND gas reservoir is likely replenished on longer timescales by efficient gas inflow from the outer disk. © ESO 2014.
|
|
| 4. |
- 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.
|
|
| 5. |
|
|
| 6. |
- Mattila, S., et al.
(författare)
-
Core collapse supernovae missed by optical surveys
- 2012
-
Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 756:2, s. 111-
-
Tidskriftsartikel (refereegranskat)abstract
- We estimate the fraction of core-collapse supernovae (CCSNe) that remain undetected by optical SN searches due to obscuration by large amounts of dust in their host galaxies. This effect is especially important in luminous and ultraluminous infrared galaxies, which are locally rare but dominate the star formation at redshifts of z similar to 1-2. We perform a detailed investigation of the SN activity in the nearby luminous infrared galaxy Arp 299 and estimate that up to 83% of the SNe in Arp 299 and in similar galaxies in the local universe are missed by observations at optical wavelengths. For rest-frame optical surveys we find the fraction of SNe missed due to high dust extinction to increase from the average local value of similar to 19% to similar to 38% at z similar to 1.2 and then remain roughly constant up to z similar to 2. It is therefore crucial to take into account the effects of obscuration by dust when determining SN rates at high redshift and when predicting the number of CCSNe detectable by future high-z surveys such as LSST, JWST, and Euclid. For a sample of nearby CCSNe (distances 6-15 Mpc) detected during the last 12 yr, we find a lower limit for the local CCSN rate of 1.5(-0.3)(+0.4) x 10(-4) yr(-1) Mpc(-3), consistent with that expected from the star formation rate. Even closer, at distances less than similar to 6 Mpc, we find a significant increase in the CCSN rate, indicating a local overdensity of star formation caused by a small number of galaxies that have each hosted multiple SNe.
|
|
| 7. |
- Kovar, Heinrich, et al.
(författare)
-
The first European interdisciplinary ewing sarcoma research summit.
- 2012
-
Ingår i: Frontiers in oncology. - : Frontiers Media SA. - 2234-943X. ; 2
-
Tidskriftsartikel (refereegranskat)abstract
- The European Network for Cancer Research in Children and Adolescents (ENCCA) provides an interaction platform for stakeholders in research and care of children with cancer. Among ENCCA objectives is the establishment of biology-based prioritization mechanisms for the selection of innovative targets, drugs, and prognostic markers for validation in clinical trials. Specifically for sarcomas, there is a burning need for novel treatment options, since current chemotherapeutic treatment protocols have met their limits. This is most obvious for metastatic Ewing sarcoma (ES), where long term survival rates are still below 20%. Despite significant progress in our understanding of ES biology, clinical translation of promising laboratory results has not yet taken place due to fragmentation of research and lack of an institutionalized discussion forum. To fill this gap, ENCCA assembled 30 European expert scientists and five North American opinion leaders in December 2011 to exchange thoughts and discuss the state of the art in ES research and latest results from the bench, and to propose biological studies and novel promising therapeutics for the upcoming European EWING2008 and EWING2012 clinical trials.
|
|
