J/MNRAS/337/641 HIPASS in Fornax (Waugh+, 2002)
The large-scale distribution of neutral hydrogen in the Fornax region.
Waugh M., Drinkwater M.J., Webster R.L., Staveley-Smith L., Kilborn V.A.,
Barnes D.G., Bhathal R., de Blok W.J.G., Boyce P.J., Disney M.J.,
Ekers R.D., Freeman K.C., Gibson B.K., Henning P.A., Jerjen H., Knezek P.M.,
Koribalski B., Marquarding M., Minchin R.F., Price R.M., Putman M.E.,
Ryder S.D., Sadler E.M., Stootman F., Zwaan M.A.
<Mon. Not. R. Astron. Soc. 337, 641 (2002)>
=2002MNRAS.337..641W 2002MNRAS.337..641W
ADC_Keywords: Clusters, galaxy ; H I data ; Radio lines ; Radial velocities
Keywords: surveys - galaxies: clusters: individual: Fornax -
galaxies: evolution - large-scale structure of the Universe -
radio lines: galaxies
Abstract:
Using data from the HI Parkes All Sky Survey (HIPASS), we have
searched for neutral hydrogen in galaxies in a region <25x25°2
centred on NGC 1399, the nominal centre of the Fornax cluster. Within
a velocity search range of 300-3700km/s and to a 3 lower flux limit of
∼40mJy, 110 galaxies with HI emission were detected, one of which is
previously uncatalogued. None of the detections has early-type
morphology. Previously unknown velocities for 14 galaxies have been
determined, with a further four velocity measurements being
significantly dissimilar to published values. Identification of an
optical counterpart is relatively unambiguous for more than ∼90 per
cent of our HI galaxies. The galaxies appear to be embedded in a sheet
at the cluster velocity which extends for more than 30across the
search area. At the nominal cluster distance of ∼20Mpc, this
corresponds to an elongated structure more than 10Mpc in extent. A
velocity gradient across the structure is detected, with radial
velocities increasing by ∼500km/s from south-east to north-west. The
clustering of galaxies evident in optical surveys is only weakly
suggested in the spatial distribution of our HI detections. Of 62 HI
detections within a 10° projected radius of the cluster centre,
only two are within the core region (projected radius <1°) and
less than 30 per cent are within 3.5°, suggesting a considerable
deficit of HI-rich galaxies in the centre of the cluster. However,
relative to the field, there is a 3(±1)-fold excess of HI-rich
galaxies in the outer parts of the cluster where galaxies may be
infalling towards the cluster for the first time.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 145 110 Properties of Fornax region detections
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See also:
VIII/73 : The HI Parkes All Sky Survey Catalogue (Meyer+, 2004)
J/AJ/123/873 : HIPASS high-velocity clouds (Putman+, 2002)
J/AJ/124/690 : H I-selected galaxies in South Celestial Cap (Kilborn+, 2002)
J/AJ/124/1954 : 1000 brightest HIPASS galaxies catalog (Ryan-Weber+, 2002)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- HIPASS HIPASS name,
[WDW2002] HIPASS JHHMM+DDa in Simbad
9 A1 --- m_HIPASS [ab] Multiplicity index on HIPASS
11- 12 I2 h RAh HI detection centre Right ascension (J2000)
14- 15 I2 min RAm HI detection centre Right ascension (J2000)
17- 20 F4.1 s RAs HI detection centre Right ascension (J2000)
22 A1 --- DE- HI detection centre Declination sign (J2000)
23- 24 I2 deg DEd HI detection centre Declination (J2000)
26- 27 I2 arcmin DEm HI detection centre Declination (J2000)
29- 30 I2 arcsec DEs HI detection centre Declination (J2000)
32- 35 I4 km/s V50 HI heliocentric systemic radial velocity
(optical convention) at the mid-point of the
50% widths from unsmoothed spectra
37- 40 I4 km/s V20 HI heliocentric systemic radial velocity
(optical convention) at the mid-point of the
20% widths from unsmoothed spectra
42- 44 I3 km/s W50 50% HI velocity width
46- 48 I3 km/s W20 20% HI velocity width
50- 54 F5.3 Jy Speak HI peak flux
56- 61 F6.2 Jy.km/s Sint Total integrated HI flux
63- 67 F5.2 mag bmag ? Apparent blue magnitude (from NED,
measurement type in n_bmag)
69- 72 A4 --- n_bmag Type of blue magnitude measurement
74- 77 F4.1 --- M/LB ? Mass-to-blue-light ratio
79- 82 I4 km/s Vel ? Optical galaxy velocity recorded in NED
84- 86 F3.1 arcmin Dist ? Projected separation of the positions of the
HI detection and the likely corresponding
optical galaxy
88-115 A28 --- OName Name(s) of the likely matching optical galaxy
117-145 A29 --- Rem Remarks (1)
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Note (1): Remarks including the names(s) of possible optical galaxy
match(es) where the match is uncertain. These detections are labelled
'C' ('confused'). Derived values shown in the table proper refer to
the galaxy named in Col. (OnName).
For detections labelled 'V diff', the H I velocity differs
significantly from the published optical value(s). The comment
'new V' indicates that a velocity measurement has not previously
been published.
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History:
From electronic version of the journal
(End) James Marcout, Patricia Bauer [CDS] 04-Feb-2003