Stellar Populations of Dwarf Galaxies

We selected a sample of dwarf galaxies in the Virgo cluster from the original catalog of Bingelli, Sandage and Tamman (1985), which have been measured at 21 cm by Hoffman et al. (1987). The original sample was selected to have both high surface brightness objects (classified as BCD or anything/BCD), and low surface brightness galaxies (classified as ImIII, ImIV or ImV). An additional selection was done on the total amount of HI, as given in Hoffman et al. We selected from each surface brightness group objects with high HI content (flux integral larger than a set threshold), and others with low HI content. We thus defined four samples differing in surface brightness level and total HI content.

Download Full-text

The σc — Vcirc correlation in high and low surface brightness galaxies

Symposium - International Astronomical Union ◽

10.1017/s0074180900183597 ◽

2004 ◽

Vol 220 ◽

pp. 339-340 ◽

Cited By ~ 1

Author(s):

A. Pizzella ◽

E. Dalla Bontà ◽

E. M. Corsini ◽

L. Coccato ◽

F. Bertola

Keyword(s):

Surface Brightness ◽

Velocity Dispersion ◽

Spiral Galaxies ◽

High Surface ◽

Linear Scale ◽

High Surface Brightness ◽

Circular Velocity ◽

Straight Line ◽

Low Surface Brightness ◽

Low Surface Brightness Galaxies

We investigate the relation between the central velocity dispersion, σc, and the circular velocity, Vcirc, in galaxies. in addition to previously obtained data, we consider an observationally homogeneus sample of 52 high surface brightness and 11 low surface brightness spiral galaxies. We performed a straight line regression analysis in a linear scale, finding a good fit, also for low σc galaxies, always rejected in the previous studies. Low surface brightness galaxies seem to behave differently, showing either higher values of Vcirc or lower values of σc with respect to their high surface brightness counterparts.

Download Full-text

Morphology and Stellar Populations in the Gas-Rich, Giant LSBGs

International Astronomical Union Colloquium ◽

10.1017/s0252921100054300 ◽

1999 ◽

Vol 171 ◽

pp. 191-195 ◽

Cited By ~ 1

Author(s):

P. Knezek

Keyword(s):

Entire Range ◽

Surface Brightness ◽

Spiral Galaxies ◽

High Surface ◽

Nuclear Spectroscopy ◽

Nuclear Activity ◽

High Surface Brightness ◽

Low Surface Brightness ◽

Show Evidence ◽

Low Surface Brightness Galaxies

AbstractAn unexpected characteristic of low surface brightness galaxies (LSBGs) is that a significant number are massive and possess substantial amounts of atomic gas. We present preliminary results of an ongoing program to obtain BVRIJHK imaging, along with some nuclear spectroscopy, of a well-defined sample of LSBGs which are gas-rich and of similar size to giant, high surface brightness spiral galaxies (HSBGs). These LSBGs span the entire range of Hubble disk morphologies. While their disks are bluer, on average, than comparable HSBGs, the optical morphology of massive LSBGs indicates that many of these systems have undergone previous star formation episodes. They typically have long disk scale lengths, and range from MB = −16 to −22 (H0 = 75 km s−1 Mpc−1). About half of the LSBGs with bulges show evidence of nuclear activity, and ~30% appear to be barred. These massive, gas-rich LSBGs apparently have varied, and often complex, evolutionary histories.

Download Full-text

Gasdynamics and Starbursts in Interacting Galaxies

Symposium - International Astronomical Union ◽

10.1017/s0074180900112641 ◽

1999 ◽

Vol 186 ◽

pp. 205-212 ◽

Cited By ~ 1

Author(s):

J. Christopher Mihos

Keyword(s):

Surface Brightness ◽

High Surface ◽

Disk Surface ◽

Interacting Galaxies ◽

Host Galaxies ◽

Direct Function ◽

High Surface Brightness ◽

Low Surface Brightness ◽

The Stability ◽

Low Surface Brightness Galaxies

The onset of gaseous inflows and central activity in interacting galaxies is driven largely by induced bars in the host galaxies. The stability of galaxies against growing bar modes is a direct function of their structural properties — galaxies with central bulges or low disk surface densities are more stable against central starbursts than are bulgeless or disk-dominated systems. Low surface brightness galaxies prove less prone to bar formation and central starbursts than do normal high surface brightness galaxies. This stability of LSB disks also resolves many of the dynamical pitfalls encountered when attempting to link poststarburst “E+A” galaxies to interactions involving normal high surface brightness galaxy progenitors.

Download Full-text

Edge-on Low Surface Brightness Galaxies in the SDSS and the Red Halo Phenomenon

Proceedings of the International Astronomical Union ◽

10.1017/s1743921306005199 ◽

2006 ◽

Vol 2 (S235) ◽

pp. 82-82

Author(s):

Brady Caldwell ◽

Nils Bergvall

Keyword(s):

Surface Brightness ◽

Stellar Population ◽

High Surface ◽

Disk Galaxies ◽

High Surface Brightness ◽

Polar Direction ◽

Low Surface Brightness ◽

Compact Galaxies ◽

Low Surface Brightness Galaxies ◽

Lsb Galaxies

AbstractExtremely red halos have been detected around high surface brightness (HSB) disk galaxies and blue compact galaxies. We analyse the halo emission of a sample of 970 stacked edge-on low surface brightness (LSB) galaxies in the SDSS (DR4) down to μg ~ 30 mag arcsec−2. These are divided by g − r colour limits into a “blue” Sample A (336 galaxies), “yellow” Sample B (318 galaxies) and “red” Sample C (316 galaxies). The gri colours indicate a prominent red excess in the polar direction, strongly deviating from any normal stellar population.

Download Full-text

Stellar populations of bulges in galaxies with a low surface-brightness disc

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314006048 ◽

2012 ◽

Vol 10 (H16) ◽

pp. 340-340

Author(s):

L. Morelli ◽

E. M. Corsini ◽

A. Pizzella ◽

E. Dalla Bontà ◽

L. Coccato ◽

...

Keyword(s):

Surface Brightness ◽

Stellar Population ◽

High Surface ◽

Line Strength ◽

Stellar Populations ◽

Element Abundance ◽

High Surface Brightness ◽

Central Value ◽

Radial Profiles ◽

Low Surface Brightness

AbstractThe radial profiles of the Hβ, Mg, and Fe line-strength indices are presented for a sample of eight spiral galaxies with a low surface-brightness stellar disc and a bulge. The correlations between the central values of the line-strength indices and velocity dispersion are consistent to those known for early-type galaxies and bulges of high surface-brightness galaxies. The age, metallicity, and α/Fe enhancement of the stellar populations in the bulge-dominated region are obtained using stellar population models with variable element abundance ratios. Almost all the sample bulges are characterized by a young stellar population, on-going star formation, and a solar α/Fe enhancement. Their metallicity spans from high to sub-solar values. No significant gradient in age and α/Fe enhancement is measured, whereas only in a few cases a negative metallicity gradient is found. These properties suggest that a pure dissipative collapse is not able to explain formation of all the sample bulges and that other phenomena, like mergers or acquisition events, need to be invoked. Such a picture is also supported by the lack of a correlation between the central value and gradient of the metallicity in bulges with very low metallicity. The stellar populations of the bulges hosted by low surface-brightness discs share many properties with those of high surface-brightness galaxies. Therefore, they are likely to have common formation scenarios and evolution histories. A strong interplay between bulges and discs is ruled out by the fact that in spite of being hosted by discs with extremely different properties, the bulges of low and high surface-brightness discs are remarkably similar.

Download Full-text

High surface brightness dwarf galaxies in the Fornax cluster

Monthly Notices of the Royal Astronomical Society ◽

10.1046/j.1365-8711.1998.01578.x ◽

1998 ◽

Vol 296 (1) ◽

pp. L15-L19 ◽

Cited By ~ 26

Author(s):

M. J. Drinkwater ◽

M. D. Gregg

Keyword(s):

Surface Brightness ◽

Dwarf Galaxies ◽

High Surface ◽

High Surface Brightness ◽

Fornax Cluster

Download Full-text

Low Surface Brightness Galaxies in Deep Surveys

International Astronomical Union Colloquium ◽

10.1017/s0252921100054142 ◽

1999 ◽

Vol 171 ◽

pp. 76-83

Author(s):

Henry C. Ferguson

Keyword(s):

Surface Brightness ◽

Dwarf Galaxies ◽

Recent Literature ◽

Solid Angle ◽

Large Space ◽

Space Density ◽

Faint Galaxy ◽

Low Surface Brightness ◽

Low Surface Brightness Galaxies ◽

Lsb Galaxies

AbstractWe examine the constraints that can be placed on the space density of low-surface-brightness galaxies from deep HST images. Such images, while covering only a small solid angle, provide enough depth and spatial resolution to detect LSB galaxies at moderate redshift and distinguish them from galaxies of higher surface brightness.We consider five simple models of the non-evolving or slowly-evolving population of LSB galaxies, motivated by various discussions in the recent literature. The basic results are (1) models with a large space-density of giant LSB galaxies at moderate redshift do not look like the real world and, (2) models with a large space-density of dwarf LSB galaxies are consistent with HST data (that is, they do not produce more faint LSB galaxies per unit solid angle than are detected at magnitudes I ≳ 23), but these LSB dwarf galaxies do not contribute much to faint galaxy counts unless they formed their stars in a rapid burst.

Download Full-text