1984
DOI: 10.1146/annurev.aa.22.090184.000345
|View full text |Cite
|
Sign up to set email alerts
|

Structure and Evolution of Irregular Galaxies

Abstract: INTRODUCTIONIrregular galaxies (Irrs) usually are smaller, less massive, and optically dimmer than commonly studied giant spirals, SOs, and classical ellipticals. At first giance they also appear to be rare objects that make up only a few percent of the major bright galaxy catalogs (87, 300). Is there then much reward in pursuing such faint and elusive galaxies? The answer to this question turns out to be a surprisingly strong "yes." An examination of more nearly complete samples of galaxies (213,341,366) reve… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
4
1

Citation Types

4
60
0

Year Published

1987
1987
2011
2011

Publication Types

Select...
5
3
1

Relationship

1
8

Authors

Journals

citations
Cited by 116 publications
(64 citation statements)
references
References 202 publications
(342 reference statements)
4
60
0
Order By: Relevance
“…Deep H i pointed observations of 59 Virgo cluster dEs from the VCC by Conselice et al (2003) yielded only 7 clear detections (just 2 of which are new) for objects having a mean blue absolute magnitude MB of -16 (range: -14.2 to -17.0) and with an average MHI =2.5±3.6 10 8 M⊙, (MHI/LB )⊙ = 0.57±0.52 and FWHM line width W50=125±93 km s −1 . Even if the expected detection rate was low, we carried out H i follow ups of a sub-sample of our galaxies, because dwarf galaxies in clusters do include star-forming, and generally H i-rich, dwarf irregulars (e.g., Gallagher & Hunter 1984) as well as quiescent, gas-poor dwarf elliptical/spheroidals (e.g., Ferguson & Binggeli 1994;Gallagher & Wyse 1994). H i observations are required for a clearer understanding of their nature, in order to confirm their cluster membership, place lower limits on the H i mass of the non-detected objects, obtain MHI /LB ratios or upper limits and look for environmental effects on their gas content.…”
Section: H I Observationsmentioning
confidence: 99%
“…Deep H i pointed observations of 59 Virgo cluster dEs from the VCC by Conselice et al (2003) yielded only 7 clear detections (just 2 of which are new) for objects having a mean blue absolute magnitude MB of -16 (range: -14.2 to -17.0) and with an average MHI =2.5±3.6 10 8 M⊙, (MHI/LB )⊙ = 0.57±0.52 and FWHM line width W50=125±93 km s −1 . Even if the expected detection rate was low, we carried out H i follow ups of a sub-sample of our galaxies, because dwarf galaxies in clusters do include star-forming, and generally H i-rich, dwarf irregulars (e.g., Gallagher & Hunter 1984) as well as quiescent, gas-poor dwarf elliptical/spheroidals (e.g., Ferguson & Binggeli 1994;Gallagher & Wyse 1994). H i observations are required for a clearer understanding of their nature, in order to confirm their cluster membership, place lower limits on the H i mass of the non-detected objects, obtain MHI /LB ratios or upper limits and look for environmental effects on their gas content.…”
Section: H I Observationsmentioning
confidence: 99%
“…Gallagher & Hunter 1984). Compared to the larger spiral galaxies, gas-rich dIrrs are smaller, bluer, metal-poor, and less luminous.…”
Section: Introductionmentioning
confidence: 99%
“…Variations in the star formation rate (SFR) in dwarf galaxies have been deduced from several observations like direct measurements of individual star formation histories (Dohm-Palmer et al 2002), a large variation in the specific SFR, or short gas depletion times (Gallagher & Hunter 1984). Especially interesting is the group of isolated starburst galaxies, because no external triggers can be invoked for their high activity.…”
Section: Introductionmentioning
confidence: 99%
“…enhanced gas densities. Already Gallagher & Hunter (1984) stressed that the observation of starburst dIrrs implies a mechanism to organise large-scale star formation which cannot operate all the time due to fast consumption of fuel. On the other hand, the instability leading to an episodic SFR should only work in a small parameter range, because most of the isolated dIrrs seem to evolve in a highly self-regulated manner.…”
Section: Introductionmentioning
confidence: 99%