Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· arXiv e-print (arXiv:0711.3232)
· On-line Data
· References in the article
· Citations to the Article (4) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (18)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Is NGC 3108 transforming itself from an early- to late-type galaxy - an astronomical hermaphrodite?
Authors:
Hau, George K. T.; Bower, Richard G.; Kilborn, Virginia; Forbes, Duncan A.; Balogh, Michael L.; Oosterloo, Tom
Affiliation:
AA(Physics Department, University of Durham, South Road, Durham DH1 3LE; Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia), AB(Physics Department, University of Durham, South Road, Durham DH1 3LE), AC(Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia), AD(Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia), AE(Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, Canada N2L 3G1), AF(ASTRON, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, the Netherlands)
Publication:
Monthly Notices of the Royal Astronomical Society, Volume 385, Issue 4, pp. 1965-1972. (MNRAS Homepage)
Publication Date:
04/2008
Origin:
MNRAS
MNRAS Keywords:
galaxies: elliptical and lenticular, cD , galaxies: general , galaxies individual: NGC 3108 , galaxies: peculiar , galaxies: spiral , galaxies: structure
DOI:
10.1111/j.1365-2966.2007.12740.x
Bibliographic Code:
2008MNRAS.385.1965H

Abstract

A common feature of hierarchical galaxy formation models is the process of `inverse' morphological transformation: a bulge dominated galaxy accretes a gas disc, dramatically reducing the system's bulge-to-disc mass ratio. During their formation, present-day galaxies may execute many such cycles across the Hubble diagram.

A good candidate for such a `hermaphrodite' galaxy is NGC 3108: a dust-lane early-type galaxy which has a large amount of HI gas distributed in a large-scale disc. We present narrow-band Hα and R-band imaging, and compare the results with the HI distribution from the literature. The emission is in two components: a nuclear bar and an extended disc component which coincides with the HI distribution. This suggests that a stellar disc is currently being formed out of the HI gas. The spatial distributions of the Hα and HI emission and the HII regions are consistent with a barred spiral structure, extending some 20 kpc in radius. We measure an extinction-corrected star formation rate (SFR) of 0.42Msolaryr-1. The luminosity function of the HII regions is similar to other spiral galaxies, with a power-law index of -2.1, suggesting that the star formation mechanism is similar to other spiral galaxies.

We measured the current disc mass and find that it is too massive to have been formed by the current SFR over the last few Gyr. It is likely that the SFR in NGC 3108 was higher in the past. With the current SFR, the disc in NGC 3108 will grow to be ~6.2 × 109Msolar in stellar mass within the next 5.5 Gyr. While this is substantial, the disc will be insignificant compared with the large bulge mass: the final stellar mass disc-to-bulge ratio will be ~0.02. NGC 3108 will fail to transform into anything resembling a spiral without a boost in the SFR and additional supply of gas.

Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints