scholarly journals The Size-Luminosity Relation of Disk Galaxies in EDisCS Clusters

2006 ◽  
Vol 2 (S235) ◽  
pp. 201-201
Author(s):  
Stephanie M. Gogarten ◽  
Julianne J. Dalcanton ◽  
Luc Simard ◽  
Gregory Rudnick ◽  
Vandana Desai ◽  
...  
Keyword(s):  
Surface Brightness ◽  
High Redshift ◽  
Disk Galaxies ◽  
Selection Effects ◽  
Distant Cluster ◽  
Cluster Survey ◽  
Low Surface Brightness ◽  
Advanced Camera For Surveys ◽  
Low Surface Brightness Galaxies

AbstractWe present the size-luminosity relation (SLR) for disk galaxies observed in eight clusters from the ESO Distant Cluster Survey (EDisCS). These clusters, at redshifts 0.4 < z < 0.8, were observed with the Hubble Space Telescope's Advanced Camera for Surveys. While we observe a change in the SLR with redshift, namely that there is an absence of low surface brightness galaxies at high redshift, we demonstrate that this could be a product of selection effects and thus is not a confirmation of evolution. We also compare the SLR for cluster and field galaxies in each redshift bin and see no significant effects of environment on the SLR.

scholarly journals Number Counts and Evolving Dwarfs

1996 ◽  
Vol 171 ◽  
pp. 431-431
Author(s):  
S. Philllipps ◽  
S.P. Driver
Keyword(s):  
Surface Brightness ◽  
High Redshift ◽  
Redshift Surveys ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies ◽  
Number Counts ◽  
Band Number

Recent redshift surveys (eg. Colless et al. 1993) have shown that the excess galaxies seen in faint B band number counts are not evolved giants at high redshift, but low to moderate luminosity objects at modest redshifts. This led to the suggestion (eg. Cowie et al. 1991) that there was once an extra population of dwarfs which has now disappeared, ie. there is nonconservation of galaxy number. We have investigated a picture in which the dwarfs have merely faded to become very low surface brightness galaxies like those now turning up in nearby clusters (eg. Turner et al. 1993).

scholarly journals 21 cm Searches for Dim Galaxies

1997 ◽  
Vol 14 (1) ◽  
pp. 69-72 ◽  
Author(s):  
Mike Disney ◽  
Gareth Banks
Keyword(s):  
Parameter Space ◽  
Surface Brightness ◽  
Selection Effects ◽  
Strong Selection ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies

AbstractWe review very strong selection effects which operate against the detection of dim (i.e. low surface brightness) galaxies. The Parkes multibeam instrument offers a wonderful opportunity to turn up new populations of such galaxies. However, to explore the newly accessible parameter space, it will be necessary to survey both a very deep patch (105 s/pointing, limiting Nhi ∼ 1018 cm−2) and a deep patch (104 s/pointing, limiting Nhi ∼ 3 × 1018 cm−2) in carefully selected areas, and we outline the case to do this.

scholarly journals The star formation histories of Low Surface Brightness galaxies

1999 ◽  
Vol 171 ◽  
pp. 245-252
Author(s):  
E.F. Bell ◽  
R.G. Bower ◽  
R.S. de Jong ◽  
B.J. Rauscher ◽  
D. Barnaby ◽  
...  
Keyword(s):  
Star Formation ◽  
Surface Brightness ◽  
Near Infrared ◽  
Large Range ◽  
Optical Data ◽  
Disk Galaxies ◽  
Infrared Images ◽  
Low Surface Brightness ◽  
Star Formation Histories ◽  
Low Surface Brightness Galaxies

AbstractNear-infrared images of a sample of red, blue and giant low surface brightness disk galaxies (LSBGs) were combined with optical data with the aim of constraining their star formation histories. Most LSBGs have strong colour gradients consistent with mean stellar age gradients. We find that LSBGs have a large range of ages and metallicities, spanning those observed in normal disk galaxies. In particular, red and blue LSBGs have very different star formation histories and represent two independent routes to low B band surface brightness. Blue LSBGs are well described by models with low, roughly constant star formation rates, whereas red LSBGs are better described by a ‘faded disk’ scenario.

scholarly journals The Central Dynamics of Blue Low Surface Brightness Galaxies

2004 ◽  
Vol 220 ◽  
pp. 335-336
Author(s):  
Erik Zackrisson ◽  
Nils Bergvall
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Surface Brightness ◽  
Cold Dark Matter ◽  
Central Density ◽  
Disk Galaxies ◽  
Rotation Curves ◽  
Central Surface ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies

We use optical, long-slit rotation curves to derive the slope of the central density profile in three blue disk galaxies with very faint central surface brightness values. We find the result to be in conflict with current cold dark matter predictions and to lend further support for pseudo-isothermal spheres as superior models for the dark halos of galaxies.

scholarly journals The HST Medium Deep Survey: Galaxy Morphology at High Redshift

1996 ◽  
Vol 168 ◽  
pp. 219-227
Author(s):  
R. E. Griffiths ◽  
K. U. Ratnatunga ◽  
S. Casertano ◽  
M. Im ◽  
L. W. Neuschaefer ◽  
...  
Keyword(s):  
Surface Brightness ◽  
High Redshift ◽  
Low Surface Brightness ◽  
Deep Survey ◽  
Compact Galaxies ◽  
Low Surface Brightness Galaxies ◽  
Blue Galaxy ◽  
Peculiar Galaxies ◽  
Galaxy Morphology

With HST and WFPC2, galaxies in the Medium Deep Survey can be reliably classified to magnitudesI814≲ 22.0 in the F814W band, at a mean redshift. The main result is the relatively high proportion (~40%) of objects which are in some way irregular or anomalous, and which are of relevance in understanding the origin of the familiar excess population of faint galaxies. These diverse objects include compact galaxies, apparently interacting pairs, galaxies with superluminous starforming regions and diffuse low surface brightness galaxies of various forms. The ‘irregulars’ and ‘peculiar’ galaxies contribute most of the excess counts in the I-band at our limiting magnitude, and may explain the ‘faint blue galaxy’ problem.

scholarly journals The Fornax Spectroscopic Survey — Low Surface Brightness Galaxies in Fornax

1999 ◽  
Vol 171 ◽  
pp. 120-127 ◽  
Author(s):  
M.J. Drinkwater ◽  
S. Phillipps ◽  
J.B. Jones
Keyword(s):  
Image Classification ◽  
Surface Brightness ◽  
Background Field ◽  
Selection Effects ◽  
Cluster Membership ◽  
Low Surface Brightness ◽  
Fornax Cluster ◽  
Low Surface Brightness Galaxies ◽  
Lsb Galaxies

AbstractThe Fornax Spectroscopic Survey is a large optical spectroscopic survey of all 14 000 objects with 16.5 < BJ < 19.7 in a 12 deg2 area of sky centered on the Fornax Cluster. We are using the 400-fibre Two Degree Field spectrograph on the Anglo-Australian Telescope: the multiplex advantage of this system allows us to observe objects conventionally classified as “stars” as well as “galaxies”. This is the only way to minimise selection effects caused by image classification or assessing cluster membership.In this paper we present the first measurements of low surface brightness (LSB) galaxies we have detected both in the Fornax Cluster and among the background field galaxies. The new cluster members include some very low luminosity (MB ≈ −11.5 mag) dwarf ellipticals, whereas the background LSB galaxies are luminous (−19.6 < MB < −17.0 mag) disk-like galaxies.

scholarly journals A first attempt to differentiate between modified gravity and modified inertia with galaxy rotation curves

2020 ◽  
Vol 636 ◽  
pp. A56 ◽  
Author(s):  
Jonas Petersen ◽  
Federico Lelli
Keyword(s):  
Modified Gravity ◽  
Surface Brightness ◽  
Analytical Models ◽  
Disk Galaxies ◽  
Rotation Curves ◽  
Quality Requirements ◽  
Modified Newtonian Dynamics ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies

The phenomenology of modified Newtonian dynamics (MOND) on galaxy scales may point to more fundamental theories of either modified gravity (MG) or modified inertia (MI). In this paper, we test the applicability of the global deep-MOND parameter Q which is predicted to vary at the 10% level between MG and MI theories. Using mock-observed analytical models of disk galaxies, we investigate several observational uncertainties, establish a set of quality requirements for actual galaxies, and derive systematic corrections in the determination of Q. Implementing our quality requirements to the SPARC database yields 15 galaxies, which are close enough to the deep-MOND regime as well as having rotation curves that are sufficiently extended and sampled. For these galaxies, the average and median values of Q seem to favor MG theories, albeit both MG and MI predictions are in agreement with the data within 1.5σ. Improved precision in the determination of Q can be obtained by measuring extended and finely-sampled rotation curves for a significant sample of extremely low-surface-brightness galaxies.

scholarly journals Kinematics of Giant Low Surface Brightness Galaxies

1999 ◽  
Vol 171 ◽  
pp. 214-220 ◽  
Author(s):  
T.E. Pickering
Keyword(s):  
Dark Matter ◽  
Surface Brightness ◽  
Dwarf Galaxies ◽  
High Sensitivity ◽  
Disk Galaxies ◽  
Optical Surface ◽  
Rotation Curves ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies ◽  
Dynamical Masses

AbstractHigh sensitivity H I observations now exist for six giant low surface brightness (LSB) disk galaxies including the two prototypes, Malin 1 (Bothun et al. 1987; Impey & Bothun 1989) and F568-6 (also known as Malin 2; Bothun et al. 1990). Their H I surface brightnesses are generally low, but proportionally not as low as their optical surface brightnesses. Their total H I masses and radial extents are quite large, however, with MHI ∼ 1010M⊙h−275 and with detectable H I out to 100 kpc h−175 or more in a couple of cases. The rotation curves of these systems rise slowly and are consistent with negligible disk contribution, similar to many previously observed dwarf galaxies. However, the peak rotation velocities of these galaxies are high (>200 km s−1) and infer high dynamical masses. These galaxies provide the some of the first examples of galaxies that are both massive and dark matter dominated.

scholarly journals Lenses and Low Surface Brightness Disks

1983 ◽  
Vol 100 ◽  
pp. 253-254
Author(s):  
A. Bosma
Keyword(s):  
Surface Brightness ◽  
Disk Galaxies ◽  
Selection Effects ◽  
Central Surface ◽  
Low Surface Brightness ◽  
The Galaxy ◽  
Intrinsic Scatter ◽  
Limiting Surface ◽  
Disk Component ◽  
Exponential Disk

The 21.65-“law” for disk galaxies has been debated ever since Freeman's (1970) paper in which he found that for 28 out of 36 galaxies the extrapolated central surface brightness of the exponential disk component I0, follows this rule with little intrinsic scatter. Some people think it significant, while others invoke selection effects. Bosma and Freeman (1982) made a new attempt to clarify this problem by studying ratios of diameters of disk galaxies on the various Sky Surveys in a region of overlap. The limiting surface brightness levels were calibrated to be 24.6 and 25.6 magn/arcsec2 for the Palomar blue prints and the SRC J films, resp. The distribution of the ratio Γ = diameter (SRC) / diameter (PAL) gives a measure of the true distribution of Io if the galaxy has an exponential disk in the brightness interval 24.6 to 25.6; e.g. Io = 21.6 corresponds to Γ = 1.32, Io = 22.6 to Γ = 1.50 and Io = 23.6 to Γ = 1.90, etc.

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