Probing the low surface brightness dwarf galaxy population of the virgo cluster

AbstractThe nature of the dwarf galaxy population as a function of location in the cluster and within different environments is investigated. We have previously described the results of a search for low surface brightness objects in data drawn from an East-West strip of the Virgo cluster (Sabatini et al(2004)) and have compared this to a large area strip outside of the cluster (Roberts et al (2004)). In this talk I compare the East-West data (sampling sub-cluster A and outward) to new data along a North-South cluster strip that samples a different region (part of sub-cluster A, and the N, M clouds) and with data obtained for the Ursa Major cluster and fields around the spiral galaxy M101. The sample of dwarf galaxies in different environments is obtained from uniform datasets that reach central surface brightness values of 26 B mag/arcsec2 and an apparent B magnitude of 21 (MB =−10 for a Virgo Cluster distance of 16 Mpc). We discuss and interpret our results on the properties and distribution of dwarf low surface brightness galaxies in the context of variuos physical processes that are thought to act on galaxies as they form and evolve.

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Very gas-rich extremely metal-poor blue void dwarfs

Proceedings of the International Astronomical Union ◽

10.1017/s1743921318006257 ◽

2018 ◽

Vol 14 (S344) ◽

pp. 400-403

Author(s):

Simon A. Pustilnik ◽

Yulia A. Perepelitsyna ◽

Alexei Y. Kniazev ◽

Evgeniya S. Egorova ◽

Jayaram N. Chengalur

Keyword(s):

Surface Brightness ◽

Stellar Population ◽

Dwarf Galaxies ◽

Dwarf Galaxy ◽

General Context ◽

Evolutionary Status ◽

Low Surface Brightness ◽

Recent Advancement ◽

Low Metallicity ◽

Galaxy Population

AbstractHalf-dozen of extreme representatives of void dwarf galaxy population were found in our study of evolutionary status of a hundred galaxies in the nearby Lynx-Cancer void. They are very gas-rich, extremely low-metallicity [7.0 < 12 + log(O/H) < ∼ 7.3] objects, with blue colours of outer parts. The colours indicate the ages of the oldest visible stellar population of one to a few Gyr. They all are intrinsically faint, mostly Low Surface Brightness dwarfs, with MB range of –9.5m to –14m. Thus, their finding is a subject of the severe observational selection. The recent advancement in search for such objects in other nearby voids resulted in doubled their total number. We summarize all available data on this group of unusual void dwarf galaxies and discuss them in the general context of very low metallicity galaxies and their possible formation and evolutionary scenarios.

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The dwarf low surface brightness galaxy population of the Virgo cluster - III. Comparisons with different environments

Monthly Notices of the Royal Astronomical Society ◽

10.1111/j.1365-2966.2007.11973.x ◽

2007 ◽

Vol 379 (3) ◽

pp. 1053-1066 ◽

Cited By ~ 11

Author(s):

S. Roberts ◽

J. Davies ◽

S. Sabatini ◽

R. Auld ◽

R. Smith

Keyword(s):

Surface Brightness ◽

Virgo Cluster ◽

Low Surface Brightness ◽

Galaxy Population

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The dwarf galaxy population as revealed by ALFALFA

Proceedings of the International Astronomical Union ◽

10.1017/s174392131800710x ◽

2018 ◽

Vol 14 (S344) ◽

pp. 464-467

Author(s):

Elizabeth A. K. Adams ◽

Catherine Ball ◽

John M. Cannon ◽

Martha P. Haynes ◽

Alec Hirschauer ◽

...

Keyword(s):

Surface Brightness ◽

Dwarf Galaxies ◽

Dwarf Galaxy ◽

Optical Counterpart ◽

Star Forming ◽

Large Numbers ◽

Low Surface Brightness ◽

Low Mass ◽

Galaxy Population ◽

Optical Surveys

AbstractThe combination of sensitivity and large sky coverage of the ALFALFA HI survey has enabled the detection of difficult to observe low mass galaxies in large numbers, including dwarf galaxies overlooked in optical surveys. Three different, but connected, studies of dwarf galaxies from the ALFALFA survey are of particular interest: SHIELD (Survey of HI in Extremely Low-mass Dwarfs), candidate gas-rich ultra-faint dwarf galaxies, and the (Almost) Dark population. SHIELD is a systematic multiwavelength study of all dwarf galaxies from ALFALFA with MHI < 107.2M⊙ and clear optical counterparts. Candidate gas-rich ultra-faint dwarf galaxies extend the dwarf galaxy population to even lower masses. These galaxies are identified as isolated HI clouds with no discernible optical counterpart but subsequent observations reveal that some are extremely faint, gas-dominated galaxies. Leo P, discovered first as an HI detection, and then found to be an actively star-forming galaxy, bridges the gap between these candidate galaxies and the SHIELD sample. The (Almost) Dark sample consists of galaxies whose optical counterparts are overlooked in current optical surveys but which are clear detections in ALFALFA. This sample includes field gas-rich ultra-diffuse galaxies. Coma P, with a peak surface brightness of only ∼26.4 mag arcsec−2 in g’, demonstrates the sort of extreme low surface brightness galaxy that can be discovered in an HI survey.

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Delayed Stellar Mass Assembly in the Low Surface Brightness Dwarf Galaxy KDG 215

The Astrophysical Journal ◽

10.3847/2041-8213/aada48 ◽

2018 ◽

Vol 864 (1) ◽

pp. L14 ◽

Cited By ~ 1

Author(s):

John M. Cannon ◽

Zili Shen ◽

Kristen B. W. McQuinn ◽

Joshua Bartz ◽

Lilly Bralts-Kelly ◽

...

Keyword(s):

Surface Brightness ◽

Dwarf Galaxy ◽

Stellar Mass ◽

Low Surface Brightness ◽

Mass Assembly

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Observing the very low surface brightness dwarfs in a deep field in the VIRGO cluster: constraints on dark matter scenarios

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731237 ◽

2017 ◽

Vol 604 ◽

pp. A59 ◽

Cited By ~ 2

Author(s):

N. Menci ◽

E. Giallongo ◽

A. Grazian ◽

D. Paris ◽

A. Fontana ◽

...

Keyword(s):

Dark Matter ◽

Surface Brightness ◽

Virgo Cluster ◽

Low Surface Brightness

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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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Rotating Halos and Heavy Disks: the Case of NGC 2915

Symposium - International Astronomical Union ◽

10.1017/s0074180900197384 ◽

2004 ◽

Vol 217 ◽

pp. 172-173

Author(s):

Frédéric S. Masset ◽

Martin Bureau

Keyword(s):

Surface Brightness ◽

Spiral Structure ◽

Dwarf Galaxy ◽

Neutral Hydrogen ◽

Dark Halo ◽

Pattern Frequency ◽

Spin Parameter ◽

Low Surface Brightness ◽

Hydrodynamical Simulations ◽

Blue Compact Dwarf Galaxy

NGC 2915 is a blue compact dwarf galaxy embedded in an extended, low surface brightness HI disk with a bar and two-armed spiral structure. Common mechanisms are unable to explain those patterns and disk dark matter or a rotating triaxial dark halo were proposed as alternatives. Hydrodynamical simulations were run for each case and compared to observations using customized column density and kinematic constraints. The spiral structure can be accounted for by an unseen bar or triaxial halo, but the large bar mass or halo pattern frequency required make it unlikely that the spiral is driven by an external perturber. In particular, the spin parameter lambda is much higher than predicted by current CDM structure formation scenarios. Massive disk models show that when the gas surface density is scaled up by a factor of about 10, the disk develops a spiral structure matching the observed one in perturbed density as well as velocity. This suggests that the disk of NGC 2915 contains much more mass than is visible tightly linked to the neutral hydrogen. A classic (quasi-)spherical halo is nevertheless still required, as increasing the disk mass further to fit the circular velocity curve would make the disk violently unstable

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VLA HI Imaging of the Low Surface Brightness Dwarf Galaxy DDO 47

International Astronomical Union Colloquium ◽

10.1017/s0252921100054373 ◽

1999 ◽

Vol 171 ◽

pp. 224-227 ◽

Cited By ~ 2

Author(s):

F. Walter ◽

E. Brinks

Keyword(s):

Surface Brightness ◽

Dwarf Galaxy ◽

Dynamical Analysis ◽

Stellar Winds ◽

Mass Model ◽

Dynamical Mass ◽

Systemic Velocity ◽

Low Surface Brightness ◽

Simple Mass ◽

Hi Shells

AbstractWe present high resolution VLA-observations of the nearby Low Surface Brightness Dwarf Galaxy DDO 47. This object shows many hole-like structures in its neutral interstellar medium. The majority of the detected H I-shells are found to be expanding. Their origin is therefore believed to be due to stellar winds of the most massive stars and their subsequent supernova (SN type II) explosions within regions of recent star formation (SF). Current SF in DDO 47 is predominantly present on the rims of the HI-shells suggesting propagating SF. At a projected distance of 20 kpc (adopting a distance to DDO 47 of 4 Mpc), a companion galaxy was detected at almost the same systemic velocity (DDO 47 B). A search for an optical identification suggests that CGCG 087-033 is the optical counterpart of the companion. A preliminary dynamical analysis based on DDO 47’s rotation curve yields that it is dark matter dominated (about 80% of its dynamical mass is in some non-visible form). A simple mass model suggests that DDO 47 is one of the ‘thickest’ dwarf galaxies studied so far.

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