Details

Autor(en) / Beteiligte

• Gavazzi, G.
• Giovanelli, R.
• Haynes, M. P.
• Fabello, S.
• Fumagalli, M.
• Kent, B. R.
• Koopmann, R. A.
• Brosch, N.
• Hoffman, G. L.
• Salzer, J. J.
• Boselli, A.

Titel

HI content and other structural properties of galaxies in the Virgo cluster from the Arecibo Legacy Fast ALFA Survey

Ist Teil von

• Astronomy and astrophysics (Berlin), 2008-04, Vol.482 (1), p.43-52

Ort / Verlag

Les Ulis: EDP Sciences

Erscheinungsjahr

2008

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• We report the results of an HI blind survey of 80 deg2 of the Virgo cluster, based on the 08° $\leq \delta \leq$ 16° strip of ALFALFA, the Arecibo Legacy Fast ALFA Survey. 187 HI sources of high significance are found providing a complete census of HI sources in this region of the Virgo cluster ($-1000<cz<3000$ km s-1) with $M_{\rm HI} \geq 10^{7.5\, \sim \,8}~M_\odot$. 156/187 (83%) sources are identified with optical galaxies from the Virgo Cluster Catalogue (Binggeli et al. 1985, AJ, 90, 1681), all but 8 with late-type galaxies. Ten sources are not associated with optical galaxies and were found to correspond to tidally-disrupted systems (see Kent et al. 2007, ApJ, 665, L15; and Haynes et al. 2007, ApJ, 665, L19). The remaining 21 (11%) are associated with galaxies that are not listed in the Virgo Cluster Catalogue. For all sources with an optical counterpart in the Sloan Digital Sky Survey, we analyzed i-band SDSS plates to measure optical structural parameters. We find that in the Virgo cluster: i) HI inhabits galaxies that are structurally similar to ordinary late-type galaxies; ii) their HI content can be predicted from their optical luminosity; iii) low surface brightness galaxies have low optical luminosity and contain small quantities of neutral hydrogen; iv) low surface brightness, massive Malin1 type galaxies are comfortably rare objects (less than 0.5%); v) there are no “dark-galaxies” with HI masses $M_{\rm HI} \geq 10^{7.5 \,\sim\, 8}~M_\odot$; vi) less than 1% of early-type galaxies contain neutral hydrogen with $M_{\rm HI} \geq 10^{7.5 \,\sim\, 8}~M_\odot$ (di Serego Alighieri et al. 2007, A&A, 474, 851).