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FLASH Early Science – discovery of an intervening HI 21-cm absorber from an ASKAP survey of the GAMA 23 field
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dc.contributor.author | Allison, J R | |
dc.contributor.author | Sadler, E M | |
dc.contributor.author | Bellstedt, S | |
dc.contributor.author | Davies, L J M | |
dc.contributor.author | Driver, S P | |
dc.contributor.author | Ellison, S L | |
dc.contributor.author | Huynh, M | |
dc.contributor.author | Kapińska, A D | |
dc.contributor.author | Mahony, E K | |
dc.contributor.author | Moss, V A | |
dc.contributor.author | Robotham, A S G | |
dc.contributor.author | Whiting, M T | |
dc.contributor.author | Curran, S J | |
dc.contributor.author | Darling, J | |
dc.contributor.author | Hotan, A W | |
dc.contributor.author | Hunstead, R W | |
dc.contributor.author | Koribalski, B S | |
dc.contributor.author | Lagos, C D P | |
dc.contributor.author | Pettini, M | |
dc.contributor.author | Pimbblet, K A | |
dc.contributor.author | Voronkov, M A | |
dc.date.accessioned | 2020-05-11T14:30:05Z | |
dc.date.available | 2020-05-11T14:30:05Z | |
dc.date.issued | 2020-05 | |
dc.identifier | 267667732 | |
dc.identifier | 1e920cef-0720-4414-85c2-fc76a69e87bf | |
dc.identifier | 000535882100045 | |
dc.identifier | 85095358115 | |
dc.identifier.citation | Allison , J R , Sadler , E M , Bellstedt , S , Davies , L J M , Driver , S P , Ellison , S L , Huynh , M , Kapińska , A D , Mahony , E K , Moss , V A , Robotham , A S G , Whiting , M T , Curran , S J , Darling , J , Hotan , A W , Hunstead , R W , Koribalski , B S , Lagos , C D P , Pettini , M , Pimbblet , K A & Voronkov , M A 2020 , ' FLASH Early Science – discovery of an intervening HI 21-cm absorber from an ASKAP survey of the GAMA 23 field ' , Monthly Notices of the Royal Astronomical Society , vol. 494 , no. 3 , pp. 3627-3641 . https://doi.org/10.1093/mnras/staa949 | en |
dc.identifier.issn | 0035-8711 | |
dc.identifier.other | crossref: 10.1093/mnras/staa949 | |
dc.identifier.uri | https://hdl.handle.net/10023/19915 | |
dc.description.abstract | 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 NHI=(1.2±0.1)×1020(Tspin/100K) 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. | |
dc.format.extent | 5802955 | |
dc.language.iso | eng | |
dc.relation.ispartof | Monthly Notices of the Royal Astronomical Society | en |
dc.subject | Galaxies: evolution | en |
dc.subject | Galaxies: high redshift | en |
dc.subject | Galaxies: ISM | en |
dc.subject | Galaxies: strucutre | en |
dc.subject | Radio: lines galaxies | en |
dc.subject | QB Astronomy | en |
dc.subject | 3rd-DAS | en |
dc.subject.lcc | QB | en |
dc.title | FLASH Early Science – discovery of an intervening HI 21-cm absorber from an ASKAP survey of the GAMA 23 field | en |
dc.type | Journal article | en |
dc.contributor.institution | University of St Andrews. School of Physics and Astronomy | en |
dc.identifier.doi | 10.1093/mnras/staa949 | |
dc.description.status | Peer reviewed | en |
dc.identifier.url | https://arxiv.org/abs/2004.00847 | en |
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