The Hi Neighborhoods Around STARBIRDS

AbstractStarbursts are finite periods of intense star formation (SF) that can dramatically impact the evolutionary state of a galaxy. Recent results suggest that starbursts in dwarf galaxies last longer and are distributed over more of the galaxy than previously thought, with star formation efficiencies (SFEs) comparable to spiral galaxies, much higher than those typical of non-bursting dwarfs. This difference might be explainable if the starburst mode is externally triggered by gravitational interactions with other nearby systems. We present new, sensitive neutral hydrogen observations of 18 starburst dwarf galaxies, which are part of the STARburst IRregular Dwarf Survey (STARBIRDS) and each were mapped with the Green Bank Telescope (GBT) and/or Parkes Telescope in order to study the low surface brightness gas distributions, a common tracer for tidal interactions.

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The Halos and Environments of Nearby Galaxies (HERON) Survey

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316011881 ◽

2016 ◽

Vol 11 (S321) ◽

pp. 186-189 ◽

Cited By ~ 1

Author(s):

R. Michael Rich ◽

Noah Brosch ◽

James Bullock ◽

Andreas Burkert ◽

Michelle Collins ◽

...

Keyword(s):

Star Formation ◽

Surface Brightness ◽

Spiral Galaxies ◽

Dwarf Galaxies ◽

Dwarf Galaxy ◽

General Survey ◽

Tidal Disruption ◽

Local Volume ◽

Low Surface Brightness ◽

Nearby Galaxies

AbstractWe have used dedicated 0.7m telescopes in California and Israel to image the halos of ~ 200 galaxies in the Local Volume to 29 mag/sq arcsec, the sample mainly drawn from the 2MASS Large Galaxy Atlas (LGA). We supplement the LGA sample with dwarf galaxies and more distant giant ellipticals. Low surface brightness halos exceeding 50 kpc in diameter are found only in galaxies more luminous than L*, and classic interaction signatures are relatively infrequent. Halo diameter is correlated with total galaxy luminosity. Extended low surface brightness halos are present even in galaxies as faint as MV = - 18. Edge-on galaxies with boxy bulges tend to lack extended spheroidal halos, while those with large classical bulges exhibit extended round halos, supporting the notions that boxy or barlike bulges originate from disks. Most face-on spiral galaxies present features that appear to be irregular extensions of spiral arms, although rare cases show smooth boundaries with no sign of star formation. Although we serendipitously discovered a dwarf galaxy undergoing tidal disruption in the halo of NGC 4449, we found no comparable examples in our general survey. A search for similar examples in the Local Volume identified hcc087, a tidally disrupting dwarf galaxy in the Hercules Cluster, but we do not confirm an anomalously large half-light radius reported for the dwarf VCC 1661.

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Gas-rich LSB Galaxies – Progenitors of Blue Compact Dwarfs?

International Astronomical Union Colloquium ◽

10.1017/s0252921100054415 ◽

1999 ◽

Vol 171 ◽

pp. 253-260 ◽

Cited By ~ 1

Author(s):

John J. Salzer ◽

Stuart A. Norton

Keyword(s):

Star Formation ◽

Surface Brightness ◽

Dwarf Galaxies ◽

Dwarf Galaxy ◽

Mass Density ◽

Central Mass ◽

Galaxy Distribution ◽

Low Surface Brightness ◽

Central Regions ◽

Lsb Galaxies

AbstractWe analyze deep CCD images of nearby Blue Compact Dwarf (BCD) galaxies in an attempt to understand the nature of the progenitors which are hosting the current burst of star formation. In particular, we ask whether BCDs are hosted by normal or low-surface-brightness dI galaxies. We conclude that BCDs are in fact hosted by gas-rich galaxies which populate the extreme high-central-mass-density end of the dwarf galaxy distribution. Such galaxies are predisposed to having numerous strong bursts of star formation in their central regions. In this picture, BCDs can only occur in the minority of dwarf galaxies, rather than being a common phase experienced by all gas-rich dwarfs.

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Star Formation Thresholds in Low Surface Brightness Dwarf Galaxies

International Astronomical Union Colloquium ◽

10.1017/s0252921100054440 ◽

1999 ◽

Vol 171 ◽

pp. 274-281

Author(s):

Liese van Zee

Keyword(s):

Star Formation ◽

Comparative Study ◽

Column Density ◽

Surface Brightness ◽

Dwarf Galaxies ◽

Critical Threshold ◽

Active Star ◽

Comparison Sample ◽

Active Star Formation ◽

Low Surface Brightness

AbstractThe results of a comparative study of star formation thresholds in gas-rich, low surface brightness, dwarf galaxies are presented. Approximately half the galaxies in the study were “high MH/LB” galaxies, which appear to have inefficient star formation properties. The comparison sample comprised of otherwise “normal” dwarf galaxies, with moderate current star formation rates. In all systems, sites of active star formation were associated with local peaks in the HI column density. For both types of galaxies, the azimuthally averaged gas column density is low. Similar to other LSB systems, the global gas densities are well below the critical threshold for star formation throughout the system. Thus, star formation is inhibited globally, but occurs locally in these gas-rich dwarf galaxies.

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The Low Surface Brightness Galaxy HIPASS1126-72

International Astronomical Union Colloquium ◽

10.1017/s0252921100054324 ◽

1999 ◽

Vol 171 ◽

pp. 204-206

Author(s):

Virginia Kilborn ◽

Erwin de Blok ◽

Lister Staveley-Smith ◽

Rachel Webster

Keyword(s):

Surface Brightness ◽

Neutral Hydrogen ◽

Sky Survey ◽

Low Surface Brightness ◽

The Galaxy

AbstractThe low surface brightness galaxy HIPASS1126-72 was detected in the HI Parkes All Sky Survey (HIPASS). The galaxy was previously listed in the Southern Galaxy Catalogue under the name SGC1124.87221. This galaxy represents a class of galaxies that we will readily detect in the HIPASS survey, which have low surface brightness in the optical, but are easily detectable in neutral hydrogen.

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Tidal Remnants and Intergalactic H II Regions

Symposium - International Astronomical Union ◽

10.1017/s0074180900198249 ◽

2004 ◽

Vol 217 ◽

pp. 486-491 ◽

Cited By ~ 3

Author(s):

Tom Oosterloo ◽

Raffaella Morganti ◽

Elaine M. Sadler ◽

Annette Ferguson ◽

Thijs van der Hulst ◽

...

Keyword(s):

Star Formation ◽

Surface Brightness ◽

Small Scale ◽

H Ii Regions ◽

Tidal Disruption ◽

Tidal Interactions ◽

Sky Survey ◽

Low Surface Brightness ◽

Intergalactic Space ◽

Star Formation Regions

We report the discovery of two small intergalactic H II regions in the loose group of galaxies around the field elliptical NGC 1490. The H II regions are located at least 100 kpc from any optical galaxy but are associated with a number of large H I clouds that are lying along an arc 500 kpc in length and that have no optical counterpart on the Digital Sky Survey. The sum of the H I masses of the clouds is almost 1010M⊙ and the largest H I cloud is about 100 kpc in size. Deep optical imaging reveals a very low surface brightness counterpart to this largest H I cloud, making this one of the H I richest optical galaxies known (MHI/LV ~ 200). Spectroscopy of the H II regions indicates that the abundance in these H II regions is only slightly sub-solar, excluding a primordial origin of the H I clouds. The H I clouds are perhaps remnants resulting from the tidal disruption of a reasonably sized galaxy, probably quite some time ago, by the loose group to which NGC 1490 belongs. Alternatively, they are remnants of the merger that created the field elliptical NGC 1490. The isolated H II regions show that star formation on a very small scale can occur in intergalactic space in gas drawn from galaxies by tidal interactions. Many such intergalactic small star formation regions may exist near tidally interacting galaxies.

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Dwarf Galaxies as Low Surface Brightness Galaxies

International Astronomical Union Colloquium ◽

10.1017/s0252921100054270 ◽

1999 ◽

Vol 171 ◽

pp. 169-176

Author(s):

Evan D. Skillman

Keyword(s):

Star Formation ◽

Surface Density ◽

Surface Brightness ◽

Dwarf Galaxies ◽

Lower Surface ◽

Current Evidence ◽

Chemical Abundance ◽

Galaxy Surveys ◽

Low Surface Brightness ◽

Lsb Galaxies

AbstractBecause of the weak correlation between surface brightness and luminosity, as galaxy surveys reach to lower surface brightnesses, increasing numbers of dwarf galaxies are found. Thus, studies of dwarf galaxies are relevant to our understanding of the low surface brightness universe. In particular, studies of nearby LSB dwarfs may help to answer questions concerning: (1) star formation in low abundance and low mass surface density envrionments, (2) star formation histories of galaxies and the relative youth of LSB galaxies, and (3) the chemical evolution of LSB galaxies. HST WFPC2 photometry of the resolved stars in nearby dwarf galaxies is particularly useful for all three questions.H II region abundances remain the best probe of current ISM abundances. Current evidence favors total mass (or luminosity) as the primary factor for determining the present day chemical abundance in both LSB and HSB galaxies. It remains possible that mass surface density (or surface brightness) may be a second controlling parameter.

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Galactic Winds in Low-Mass Galaxies

Proceedings of the International Astronomical Union ◽

10.1017/s1743921319000085 ◽

2018 ◽

Vol 14 (S344) ◽

pp. 301-304

Author(s):

Kristen B. W. McQuinn ◽

Liese van Zee ◽

Evan D. Skillman

Keyword(s):

Surface Brightness ◽

Dwarf Galaxies ◽

Critical Role ◽

Ionized Gas ◽

Stellar Feedback ◽

Galactic Winds ◽

Low Surface Brightness ◽

The Galaxy ◽

Show Evidence ◽

Low Mass

AbstractMass-loss via stellar-feedback driven outflows is predicted to play a critical role in the baryon cycle of low-mass galaxies. However, observational constraints on warm winds are limited as outflows are transient, intrinsically low-surface brightness events and, thus, difficult to detect. Here, we search for outflows in a sample of eleven nearby starburst dwarf galaxies which are strong candidates for outflows. Despite deep H? imaging on galaxies, only a fraction of the sample show evidence of winds. The spatial extent of all detected ionized gas is limited and would still be considered part of the ISM by simulations. These new observations indicate that the physical extent of warm phase outflows is modest and most of the mass will be recycled to the galaxy. The sample is part of the panchromatic STARBurst IRegular Dwarf Survey (STARBIRDS) designed to characterize the starburst phenomenon and its impact on the evolution of low-mass galaxies.

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Photometric Structure and Star Formation in Blue Compact Dwarf Galaxies

Proceedings of the International Astronomical Union ◽

10.1017/s1743921306006922 ◽

2006 ◽

Vol 2 (S235) ◽

pp. 327-327

Author(s):

P. Papaderos

Keyword(s):

Star Formation ◽

Surface Brightness ◽

Dwarf Galaxies ◽

Dwarf Galaxy ◽

Star Formation History ◽

Host Galaxy ◽

Star Forming ◽

Formation History ◽

Low Surface Brightness ◽

Low Mass

The star-formation history and chemodynamical evolution of Blue Compact Dwarf (BCD) galaxies are central issues in dwarf galaxy research. In spite of being old in their vast majority, BCDs resemble in many aspects unevolved low-mass galaxies in the early universe. They are gas-rich (Hi mass fraction of typically > 30%) and metal-deficient (7.1 $\la$ 12+log(O/H) $\la$ 8.3) extragalactic systems, undergoing intense star-forming (SF) activity within an underlying low-surface brightness (LSB) host galaxy.

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