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- Fomalont, E. B., et al.
(author)
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THE 2014 ALMA LONG BASELINE CAMPAIGN: AN OVERVIEW
- 2015
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In: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 808:1
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Journal article (peer-reviewed)abstract
- A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to similar to 15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from 2014 September to late November, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C 138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at similar to 350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy.
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| 2. |
- Santangelo, James S., et al.
(author)
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Global urban environmental change drives adaptation in white clover
- 2022
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 375
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Journal article (peer-reviewed)abstract
- Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural dines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale.
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| 4. |
- Swinbank, A. M., et al.
(author)
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An ALMA survey of sub-millimetre Galaxies in the Extended Chandra Deep Field South: the far-infrared properties of SMGs
- 2014
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In: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 438:2, s. 1267-1287
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Journal article (peer-reviewed)abstract
- We exploit Atacama Large Millimeter Array (ALMA) 870 mu m observations of sub-millimetre sources in the Extended Chandra Deep Field South to investigate the far-infrared properties of high-redshift sub-millimetre galaxies (SMGs). Using the precisely located 870 mu m ALMA positions of 99 SMGs, together with 24 mu m and radio imaging, we deblend the Herschel/SPIRE imaging to extract their far-infrared fluxes and colours. The median redshifts for ALMA LESS (ALESS) SMGs which are detected in at least two SPIRE bands increases with wavelength of the peak in their spectral energy distributions (SEDs), with z = 2.3 +/- 0.2, 2.5 +/- 0.3 and 3.5 +/- 0.5 for the 250, 350 and 500 mu m peakers, respectively. 34 ALESS SMGs do not have a >3 sigma counterpart at 250, 350 or 500 mu m. These galaxies have a median photometric redshift derived from the rest-frame UV-mid-infrared SEDs of z = 3.3 +/- 0.5, which is higher than the full ALESS SMG sample; z = 2.5 +/- 0.2. We estimate the far-infrared luminosities and characteristic dust temperature of each SMG, deriving L-IR = (3.0 +/- 0.3) x 10(12) L-circle dot (SFR = 300 +/- 30 M-circle dot yr(-1)) and T-d = 32 +/- 1 K. The characteristic dust temperature of these high-redshift SMGs is Delta T-d = 3-5K lower than comparably luminous galaxies at z = 0, reflecting the more extended star formation in these systems. We show that the contribution of S-870 mu m >= 1 mJy SMGs to the cosmic star formation budget is 20 per cent of the total over the redshift range z similar to 1-4. Adopting an appropriate gas-to-dust ratio, we estimate a typical molecular mass of the ALESS SMGs of M-H2 = (4.2 +/- 0.4) x 10(10) M-circle dot. Finally, we show that SMGs with S-870 mu m > 1 mJy (L-IR greater than or similar to 10(12) L-circle dot) contain similar to 10 per cent of the z similar to 2 volume-averaged H-2 mass density.
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| 5. |
- Arun, K. G., et al.
(author)
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New horizons for fundamental physics with LISA
- 2022
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In: Living Reviews in Relativity. - : Springer Science and Business Media LLC. - 1433-8351 .- 2367-3613. ; 25:1
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Research review (peer-reviewed)abstract
- The Laser Interferometer Space Antenna (LISA) has the potential to reveal wonders about the fundamental theory of nature at play in the extreme gravity regime, where the gravitational interaction is both strong and dynamical. In this white paper, the Fundamental Physics Working Group of the LISA Consortium summarizes the current topics in fundamental physics where LISA observations of gravitational waves can be expected to provide key input. We provide the briefest of reviews to then delineate avenues for future research directions and to discuss connections between this working group, other working groups and the consortium work package teams. These connections must be developed for LISA to live up to its science potential in these areas.
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| 6. |
- Fogasy, Judit, 1988, et al.
(author)
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On the frequency of star-forming galaxies in the vicinity of powerful AGNs: The case of SMM J04135+10277
- 2017
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 597
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Journal article (peer-reviewed)abstract
- Context. In the last decade several massive molecular gas reservoirs were found 108M, and 0.3% have at least one highly star-forming companion (SFR> 100 M yr-1). Conclusions. Our results suggest that quasar-gas-rich companion galaxy systems are common phenomena in the early Universe and the high incidence of companions makes the study of such systems crucial to understand the growth and hierarchical build-up of galaxies and black holes.
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| 7. |
- Fogasy, Judit, 1988, et al.
(author)
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SMM J04135+10277: a distant QSO-starburst system caught by ALMA
- 2020
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In: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 493:3, s. 3744-3756
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Journal article (peer-reviewed)abstract
- The gas content of galaxies is a key factor for their growth, starting from star formation and black hole accretion to galaxy mergers. Thus, characterizing its properties through observations of tracers like the CO emission line is of big importance in order to understand the bigger picture of galaxy evolution. We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of dust continuum, CO(5-4) and CO(8-7) line emission in the quasar-star-forming companion system SMM J04135+10277 (z = 2.84). Earlier low-J CO studies of this system found a huge molecular gas reservoir associated with the companion galaxy, while the quasar appeared gas-poor. Our CO observations revealed that the host galaxy of the quasar is also gas-rich, with an estimated molecular gas mass of ∼ (0.7-2.3)× 10^{10} M_{☉}. The CO line profiles of the companion galaxy are very broad (∼ 1000 km s^{-1}), and show signs of rotation of a compact, massive system. In contrast to previous far-infrared observations, we resolve the continuum emission and detect both sources, with the companion galaxy dominating the dust continuum and the quasar having a ∼ 25{{ per cent}} contribution to the total dust emission. By fitting the infrared spectral energy distribution of the sources with MR-MOOSE and empirical templates, the infrared luminosities of the quasar and the companion are in the range of L_{IR, QSO}∼ (2.1-9.6)× 10^{12} L_{☉} and L_{IR, Comp.}∼ (2.4-24)× 10^{12} L_{☉}, while the estimated star formation rates are ∼ 210-960 and ∼ 240-2400 M_{☉} yr^{-1}, respectively. Our results demonstrate that non-detection of low-J CO transition lines in similar sources does not necessarily imply the absence of massive molecular gas reservoir but that the excitation conditions favour the excitation of high-J transitions.
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