Low Surface Brightness Galaxy Population Research Articles

The Nature of Low-surface-brightness Galaxies in the Hyper Suprime-Cam Survey

We present the statistical redshift distribution of a large sample of low-surface-brightness (LSB) galaxies identified in the first 200 deg2 of the Hyper Suprime-Cam Strategic Survey Program. Through cross-correlation with the NASA–SDSS Atlas, we find that the majority of objects lie within z < 0.15 or ∼500 Mpc, yielding a mass range of M * ≈ 107−109 M ⊙ and a size range of r eff,g ≈ 1−8 kpc. We find a peak in the distance distribution within 100 Mpc, corresponding mostly to ∼107 M ⊙ galaxies that fall on the known mass–size relation. There is also a tail in the redshift distribution out to z ≈ 0.15, comprising more massive (M * = 108 − 109 M ⊙) galaxies at the larger end of our size range. We see tentative evidence that at the higher-mass end (M * > 108 M ⊙), the LSB galaxies do not form a smooth extension of the mass–size relation of higher-surface-brightness galaxies, perhaps suggesting that the LSB galaxy population is distinct in its formation path.

An expanded catalogue of low surface brightness galaxies in the Coma cluster using Subaru/Suprime-Cam

ABSTRACT We present a catalogue of low surface brightness (LSB) galaxies in the Coma cluster obtained from deep Subaru/Suprime-Cam V- and R-band imaging data within a region of $\mathord {\sim }4$ deg2. We increase the number of LSB galaxies presented in Yagi et al. (2016) by a factor of $\mathord {\sim }3$ and report the discovery of 29 new ultradiffuse galaxies (UDGs). We compile the largest sample of UDGs with colours and structural parameters in the Coma cluster. While most UDGs lie along the red-sequence relation of the colour–magnitude diagram, $\mathord {\sim }16$ per cent are outside (bluer or redder) the red-sequence region of Coma cluster galaxies. Our analyses show that there is no special distinction in the basic photometric parameters between UDGs and other LSB galaxies. We investigate the clustercentric colour distribution and find a remarkable transition at a projected radius of $\mathord {\sim }0.6$ Mpc. Within this cluster core region and relative to the red-sequence of galaxies, LSB galaxies are on average redder than co-spatial higher surface brightness galaxies at the 2σ level, highlighting how vulnerable LSB galaxies are to the physical processes at play in the dense central region of the cluster. The position of the transition radius agrees with expectations from recent cosmological simulation of massive galaxy clusters within which ancient infalls are predicted to dominate the LSB galaxy population.

Ultra-diffuse Galaxies Are a Subset of Cluster Dwarf Elliptical/Spheroidal Galaxies

Since 2015 there has been a great deal of interest in a supposed new class of galaxy called Ultra Diffuse Galaxies (UDGs). These are large systems with sizes $> 1.5$ kpc and have surface brightness values which are $\mu > 25$ mag arcsec$^{-2}$. Because of their low-surface brightness they are proposed to be `failed' Milky Way type galaxies given their similar size, but much lower stellar masses. As such, these systems are considered by some as a new type of galaxy, yet we show that they are a subset of a well-established and well studied population of low-surface brightness galaxies found mostly in dense areas of the universe - clusters of galaxies. We argue based on previous literature that the most likely method for forming these galaxies is through cluster processes such as `Galaxy Harassment', where through multiple high speed encounters an infalling galaxy is gradually removed of its mass, until it resembles a dwarf elliptical. Future studies of UDGs should consider the above and their more general connection to previously studied populations.

A population of faint low surface brightness galaxies in the Perseus cluster core

We present the detection of 89 low surface brightness (LSB), and thus low stellar density galaxy candidates in the Perseus cluster core, of the kind named "ultra-diffuse galaxies", with mean effective V-band surface brightnesses 24.8-27.1 mag arcsec$^{-2}$, total V-band magnitudes -11.8 to -15.5 mag, and half-light radii 0.7-4.1 kpc. The candidates have been identified in a deep mosaic covering 0.3 square degrees, based on wide-field imaging data obtained with the William Herschel Telescope. We find that the LSB galaxy population is depleted in the cluster centre and only very few LSB candidates have half-light radii larger than 3 kpc. This appears consistent with an estimate of their tidal radius, which does not reach beyond the stellar extent even if we assume a high dark matter content (M/L=100). In fact, three of our candidates seem to be associated with tidal streams, which points to their current disruption. Given that published data on faint LSB candidates in the Coma cluster - with its comparable central density to Perseus - show the same dearth of large objects in the core region, we conclude that these cannot survive the strong tides in the centres of massive clusters.

Environment, morphology, and stellar populations of bulgeless low surface-brightness galaxies

Based on the Sloan Digital Sky Survey DR 7, we investigate the environment, morphology and stellar population of bulgeless low surface brightness (LSB) galaxies in a volume-limited sample with redshift ranging from 0.024 to 0.04 and $M_r$ $\leq$ $-18.8$. The local density parameter $\Sigma_5$ is used to trace their environments. We find that, for bulgeless galaxies, the surface brightness does not depend on the environment. The stellar populations are compared for bulgeless LSB galaxies in different environments and for bulgeless LSB galaxies with different morphologies. The stellar populations of LSB galaxies in low density regions are similar to those of LSB galaxies in high density regions. Irregular LSB galaxies have more young stars and are more metal-poor than regular LSB galaxies. These results suggest that the evolution of LSB galaxies may be driven by their dynamics including mergers rather than by their large scale environment.

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

We have previously described the results of a search for low surface brightness (LSB) objects in data drawn from an east–west strip of the Virgo cluster and have compared this to a large-area strip outside the cluster. In this paper, we compare the cluster east–west data with new data along a cluster north–south strip and with data obtained for the Ursa Major (UMa) cluster and fields around the spiral galaxy M101. Our intention is to look for differences in the nature of the dwarf galaxy population with location in the cluster and within other environments. These uniform data sets reach central surface brightness values of ∼26 Bμ, and an apparent B magnitude of 21 (M(B)=−10 for a Virgo cluster distance of 16 Mpc). Over a north–south strip area of ∼15 deg(2), we find ∼22 LSB objects per square degree. This compares with ∼4 deg(−2) in both the UMa and the M101 fields. These results are very similar to what we have previously found for the east–west cluster strip and for other fields outside the cluster. There are far more small LSB features detected in Virgo cluster fields and we associate them with an extensive cluster dwarf galaxy population. In the cluster north–south strip there is an average dwarf-to-giant number ratio of 31 ± 9, which is much higher than would be expected from observations of galaxies in the Local Group, but significantly less than that required by Λ cold dark matter galaxy formation models. The dwarf-to-giant ratios in UMa and M101 are consistent with those in the Local Group. Comparing the cluster east–west and north–south data, we find clear differences in the way the number density of dwarfs decreases with cluster radius and the distributions of galaxy magnitudes and sizes. The north–south strip covers a region of the cluster that contains not only the main cluster region associated with M87, but also two more distant infalling clouds. Additionally, the north–south strip lies approximately along the extended filamentary structure associated with Virgo while the east–west strip is perpendicular to it. We interpret the differences between the two strips as being due to these different environments. We suggest that the Virgo cluster is assembling itself out of subclusters and clouds that are already rich in dwarf galaxies compared to the environment of the general field. There is no evidence for any systematic difference in dwarf galaxy (B−I) colour between dwarf galaxies of different magnitudes or in different parts of the Virgo cluster. A typical value of (B−I)= 1.8 is consistent with the colours of a wide range of stellar systems including the globular clusters of the central elliptical galaxy M87, but is bluer than is typical for giant ellipticals. We discuss and interpret our results in the context of various physical processes that are thought to act on galaxies as they form and evolve. Additionally, we give images and positions of possible new dwarf galaxy companions of M101.

An optical search for low surface brightness galaxies in the Arecibo HI Strip Survey

In order to estimate the contribution of low surface brightness (LSB) galaxies to the local (z 18 at the limiting surface brightness of mu_{B,lim}=25.2+-0.31 mag/arcsec^2. Of these 306 galaxies, 148 were not catalogued previously. Our results indicate that low surface brightness galaxies contribute at least to 30 % to the local galaxy number density. Without additional distance information, choosing the limiting diameter and the surface brightness at which the diameter is measured is crucial. Depending on these choices, diameter-limited optical catalogues are either biased against LSB galaxies, or contaminated with cosmologically dimmed high surface brightness galaxies, which affects the implied surface brightness distribution. The comparison to the AHISS showed that although optical surveys detect more galaxies per deg^2 than HI surveys, their drawback is the need for spectroscopic follow up observations to derive distances. Blind HI surveys have no diameter limits, but tend to miss gas-poor galaxies and all galaxies which lie outside their redshift limits. HI and optical surveys thus provide complementary information and sample different parts of the LSB galaxy population.

The dwarf low surface brightness galaxy population of the Virgo Cluster - II. Colours and H i line observations

n order to investigate the nature of dwarf low surface brightness (LSB) galaxies we have undertaken a deep B- and I-band CCD survey of a 14-deg2 strip in the Virgo Cluster and applied a Fourier convolution technique to explore its dwarf galaxy population down to a central surface brightness of ∼26 B mag arcsec−2 and a total absolute B mag of ∼−10. In this paper we carry out an analysis of their morphology, (B−I) colours and atomic hydrogen content. We compare these properties with those of dwarf galaxies in other environments to try and assess how the cluster environment has influenced their evolution. Field dwarfs are generally of a more irregular morphology, are bluer and contain relatively more gas. We assess the importance that various physical processes have on the evolution of cluster dwarf galaxies (ram-pressure stripping, tidal interactions, supernova-driven gas loss). We suggest that enhanced star formation triggered by tidal interactions is the major reason for the very different general properties of cluster dwarfs: they have undergone accelerated evolution.

Dynamical Evolution of Galaxies in Clusters

Tidal forces acting on galaxies in clusters lead to a strong dynamical evolution. In order to quantify the amount of evolution, I run self-consistent N-body simulations of disk galaxies for a variety of models in the hierarchically forming clusters. The tidal field along the galactic orbits is extracted from the simulations of cluster formation in the Ω0 = 1, 0.4, and 0.4, ΩΛ = 0.6 cosmological scenarios. For large spiral galaxies with a rotation speed of 250 km s-1, tidal interactions truncate massive dark matter halos at 30 ± 6 kpc and thicken stellar disks by a factor of 2-3, increasing Toomre's parameter to Q ≳ 2 and halting star formation. Low-density galaxies, such as the dwarf spheroidals with a circular velocity of 20 km s-1 and the extended low surface brightness galaxies with a scale length of 10-15 kpc, are completely disrupted by tidal shocks. Their debris contribute to the diffuse intracluster light. The tidal effects are significant not only in the core but throughout the cluster and can be parametrized by the critical tidal density. The tidally induced evolution results in the transformation of the infalling spirals into S0 galaxies and in the depletion of the low surface brightness galaxy population. In the low-Ω0 cosmological models, clusters form earlier and produce stronger evolution of galaxies.

The luminosity function and surface brightness distribution of H I selected galaxies

We measure the B-band optical luminosity function (LF) for galaxies selected in a blind H-i survey. The total LF of the H-i selected sample is flat, with Schechter parameters and , in good agreement with LFs of optically selected late-type galaxies. Bivariate distribution functions of several galaxy parameters show that the H-i density in the local Universe is more widely spread over galaxies of different size, central surface brightness and luminosity than the optical luminosity density is. The number density of very low surface brightness (LSB) (>24.0-mag-arcsec−2) gas-rich galaxies is considerably lower than that found in optical surveys designed to detect dim galaxies. This suggests that only a part of the population of LSB galaxies is gas-rich and that the rest must be gas-poor. However, we show that this gas-poor population must be cosmologically insignificant in baryon content. The contribution of gas-rich LSB galaxies (>23.0-mag-arcsec−2) to the local cosmological gas and luminosity density is modest and per cent respectively); their contribution to Ωmatter is not well-determined, but probably <11 per cent. These values are in excellent agreement with the low redshift results from the Hubble Deep Field.

Damped [CLC]Lyα[/CLC] Absorption from a Nearby Low Surface Brightness Galaxy

Ground-based & HST images of the nearby galaxy SBS 1543+593 (z=0.009) show it to be a Low Surface Brightness (LSB) galaxy with a central surface brightness of mu_B(0)=23.2 mag/arcsec-2 and scale length 0.9 h-1 kpc, values typical for the local LSB galaxy population. The galaxy lies directly in front of the QSO HS 1543+5921 (z=0.807); an HST STIS spectrum of the quasar reveals a damped Lyman-alpha (DLA) line at the redshift of the interloper with an HI column density of log N(HI) = 20.35, as well as several low-ionization metal lines with strengths similar to those found in the Milky Way interstellar medium. Our data show that LSB galaxies are certainly able to produce the DLA lines seen at higher redshift, and fuels the speculation that LSB galaxies are a major contributor to that population of absorbers.

The Effects of Starbursts and Low Surface Brightness Galaxies on Faint Galaxy Models

We present models predicting the magnitude, redshift, and color distributions of field galaxies. We explore whether a fading starburst scenario can account for the observations of faint blue galaxies. We marginally rule out a starburst scenario with a local initial mass function (IMF) because the models predict too many nearby faint galaxies that are not observed. A burst model with a truncated IMF reproduces the counts and redshift distributions well but produces too blue a population. We show that surface brightness selection has a significant effect on the distributions. In particular, adding a population of low-surface brightness galaxies, known to exist locally, can explain the counts for B<SUB>J</SUB> &lt; 23. They do not, however, account for the steepness of the counts at fainter magnitudes. Finally, we show that the colors of galaxies in a K-band-selected sample are too blue to be consistent with a constant star formation rate, passive-evolution model.

The Contribution of Low Surface Brightness Galaxies to Faint Galaxy Counts

view Abstract Citations (80) References (90) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Contribution of Low Surface Brightness Galaxies to Faint Galaxy Counts Ferguson, Henry C. ; McGaugh, Stacy S. Abstract Recent observations have revealed a population of blue galaxies at intermediate redshift with a space density well in excess of expectations from the local luminosity function and standard cosmology. The colors and luminosities of these faint blue galaxies are similar to nearby low surface brightness (LSB) galaxies. Such galaxies are severely underrepresented in surveys used to define the local luminosity function, but could in principle be detected in deep surveys. If LSB galaxy density is high enough, the faint-galaxy counts could be explained without requiring rapid galaxy evolution. To explore the consequences of including LSB galaxies, we construct catalogs of simulated nonevolving galaxies drawn from a multivariate distribution of galaxy luminosities, central surface brightnesses, bulge/disk ratios, and spectral-energy distributions. We compare two models dominated by LSB galaxies to a "standard" nonevolving model. Model galaxies are convolved with seeing and selected in a manner that closely matches real surveys. For each model we compute the local Bj band luminosity function, H I mass function, number counts in the Bj, I, and K bands, redshift distributions and color distributions. We find it possible to include a large population of LSB galaxies and incorporate a steep faint-end slope of the luminosity function in our simulations without violating the constraints on the local field-galaxy luminosity function or the H I mass function. For q0 = 0.5, the most favorable model matches the counts to B = 23, but falls short of the observations at fainter magnitudes. The discrepancy at faint magnitudes is smaller in the I and K bands. The colors and redshift distributions remain roughly consistent with observations to B = 24. The most serious discrepancy with observations is in the distribution of re at faint magnitudes, suggesting that the model contains too many LSB galaxies. Nevertheless, the results suggest that LSB galaxies could be a significant contributor to faint-galaxy counts, reducing the need for such extreme models of galaxy evolution as rapid merging or bursting dwarf galaxies. We propose several tests to assess the contribution of LSB galaxies to faint galaxy counts and to differentiate models involving moderate galaxy evolution from models involving rapid merging or starbursts. Publication: The Astrophysical Journal Pub Date: February 1995 DOI: 10.1086/175289 arXiv: arXiv:astro-ph/9409071 Bibcode: 1995ApJ...440..470F Keywords: COSMOLOGY: OBSERVATIONS; GALAXIES: LUMINOSITY FUNCTION; MASS FUNCTION; GALAXIES: PHOTOMETRY; Astrophysics E-Print: 39p, uuencoded compressed postscript, 18/21 figs included, full paper from http://planxty.stsci.edu:1024/ ferguson/lsb/lsbpp_b.ps,STScI 874 full text sources arXiv | ADS | data products SIMBAD (2)