Data

Data from: FLASH early science - discovery of an intervening H I 21-cm absorber from an ASKAP survey of the GAMA 23 field

The University of Western Australia
Allison, James R. ; Sadler, Elaine M. ; Bellstedt, Sabine ; Davies, Luke ; Driver, Simon ; Ellison, S. L. ; Huynh, Minh ; Kapinska, Anna ; Mahony, Elizabeth K. ; Moss, Vanessa ; Robotham, Aaron ; Whiting, Matthew T. ; Curran, S. J. ; Darling, Jeremy K. ; Hotan, A.W. ; Hunstead, Richard W. ; Koribalski, Bärbel ; Lagos Urbina, Claudia ; Pettini, Max ; Pimbblet, Kevin ; Voronkov, Maxim A.
Viewed: [[ro.stat.viewed]] Cited: [[ro.stat.cited]] Accessed: [[ro.stat.accessed]]
ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2FANDS&rft_id=https://research-repository.uwa.edu.au/en/datasets/58ab8dc3-23d7-4a5d-a2db-9a5627122f59&rft.title=Data from: FLASH early science - discovery of an intervening H I 21-cm absorber from an ASKAP survey of the GAMA 23 field&rft.identifier=58ab8dc3-23d7-4a5d-a2db-9a5627122f59&rft.publisher=SAO/NASA Astrophysics Data System (ADS)&rft.description=We present early science results from the First Large Absorption Survey in H I (FLASH), a spectroscopically blind survey for 21-cm absorption lines in cold hydrogen (H I) gas at cosmological distances using the Australian Square Kilometre Array Pathfinder (ASKAP). We have searched for H I absorption towards 1253 radio sources in the GAMA 23 field, covering redshifts between z = 0.34 and 0.79 over a sky area of approximately 50 deg2. In a purely blind search, we did not obtain any detections of 21-cm absorbers above our reliability threshold. Assuming a fiducial value for the H I spin temperature of Tspin = 100 K and source covering fraction cf = 1, the total comoving absorption path-length sensitive to all Damped Lyman α Absorbers (DLAs; NH I ≥ 2 × 1020 cm−2) is ΔX = 6.6 ± 0.3 (Δz = 3.7 ± 0.2) and super-DLAs (NH I ≥ 2 × 1021 cm−2) is ΔX = 111 ± 6 (Δz= 63 ± 3). We estimate upper limits on the H I column density frequency distribution function that are consistent with measurements from prior surveys for redshifted optical DLAs, and nearby 21-cm emission and absorption. By cross-matching our sample of radio sources with optical spectroscopic identifications of galaxies in the GAMA 23 field, we were able to detect 21-cm absorption at z = 0.3562 towards NVSS J224500−343030, with a column density of NH I = (1.2 ± 0.1) × 1020 (Tspin/100 K) cm−2. The absorber is associated with GAMA J22450.05−343031.7, a massive early-type galaxy at an impact parameter of 17 kpc with respect to the radio source and which may contain a massive (MH I ≿ 3 × 109 M☉) gas disc. Such gas-rich early types are rare, but have been detected in the nearby Universe.&rft.creator=Allison, James R. &rft.creator=Sadler, Elaine M. &rft.creator=Bellstedt, Sabine &rft.creator=Davies, Luke &rft.creator=Driver, Simon &rft.creator=Ellison, S. L. &rft.creator=Huynh, Minh &rft.creator=Kapinska, Anna &rft.creator=Mahony, Elizabeth K. &rft.creator=Moss, Vanessa &rft.creator=Robotham, Aaron &rft.creator=Whiting, Matthew T. &rft.creator=Curran, S. J. &rft.creator=Darling, Jeremy K. &rft.creator=Hotan, A.W. &rft.creator=Hunstead, Richard W. &rft.creator=Koribalski, Bärbel &rft.creator=Lagos Urbina, Claudia &rft.creator=Pettini, Max &rft.creator=Pimbblet, Kevin &rft.creator=Voronkov, Maxim A. &rft.date=2020&rft.relation=http://research-repository.uwa.edu.au/en/publications/e3736d02-6ac2-4ec2-9416-d10caf1ddee5&rft_subject=galaxies: evolution&rft_subject=galaxies: high-redshift&rft_subject=galaxies: ISM&rft_subject=galaxies: structure&rft_subject=radio lines: galaxies&rft_subject=Astrophysics - Astrophysics of Galaxies&rft.type=dataset&rft.language=English Access the data

Access:

Open

Full description

We present early science results from the First Large Absorption Survey in H I (FLASH), a spectroscopically blind survey for 21-cm absorption lines in cold hydrogen (H I) gas at cosmological distances using the Australian Square Kilometre Array Pathfinder (ASKAP). We have searched for H I absorption towards 1253 radio sources in the GAMA 23 field, covering redshifts between z = 0.34 and 0.79 over a sky area of approximately 50 deg2. In a purely blind search, we did not obtain any detections of 21-cm absorbers above our reliability threshold. Assuming a fiducial value for the H I spin temperature of Tspin = 100 K and source covering fraction cf = 1, the total comoving absorption path-length sensitive to all Damped Lyman α Absorbers (DLAs; NH I ≥ 2 × 1020 cm−2) is ΔX = 6.6 ± 0.3 (Δz = 3.7 ± 0.2) and super-DLAs (NH I ≥ 2 × 1021 cm−2) is ΔX = 111 ± 6 (Δz= 63 ± 3). We estimate upper limits on the H I column density frequency distribution function that are consistent with measurements from prior surveys for redshifted optical DLAs, and nearby 21-cm emission and absorption. By cross-matching our sample of radio sources with optical spectroscopic identifications of galaxies in the GAMA 23 field, we were able to detect 21-cm absorption at z = 0.3562 towards NVSS J224500−343030, with a column density of NH I = (1.2 ± 0.1) × 1020 (Tspin/100 K) cm−2. The absorber is associated with GAMA J22450.05−343031.7, a massive early-type galaxy at an impact parameter of 17 kpc with respect to the radio source and which may contain a massive (MH I ≿ 3 × 109 M☉) gas disc. Such gas-rich early types are rare, but have been detected in the nearby Universe.

Notes

External Organisations
ARC Centre of Excellence for Astrophysics in Three Dimensions (ASTRO3D); University of Oxford; Commonwealth Scientific & Industrial Research Organisation; University of Sydney; CSIRO - Australia Telescope National Facility; Netherlands Foundation for Research in Astronomy; Victoria University of Wellington; Carnegie Institution of Washington; University of Colorado Boulder; CSIRO - Space and Astronomy; Western Sydney University; Monash University (Australia); University of Hull
Associated Persons
Max Pettini (Creator)James R. Allison (Creator); Elaine M. Sadler (Creator); S. L. Ellison (Creator); Elizabeth K. Mahony (Creator); Vanessa Moss (Creator); Matthew T. Whiting (Creator); S. J. Curran (Creator); Jeremy K. Darling (Creator); A.W. Hotan (Creator); Richard W. Hunstead (Creator); Bärbel Koribalski (Creator); Kevin Pimbblet (Creator); Maxim A. Voronkov (Creator)

Issued: 2020-05

This dataset is part of a larger collection

Click to explore relationships graph
Subjects

User Contributed Tags    

Login to tag this record with meaningful keywords to make it easier to discover

Identifiers
  • global : 58ab8dc3-23d7-4a5d-a2db-9a5627122f59