We have produced a new conformal map of the universe illustrating recent discoveries, ranging from Kuiper belt objects in the Solar system, to the galaxies and quasars from the Sloan Digital Sky Survey. This map projection, based on the logarithm map of the complex plane, preserves shapes locally, and yet is able to display the entire range of astronomical scales from the Earth’s neighborhood to the cosmic microwave background. The conformal nature of the projection, preserving shapes locally, may be of particular use for analyzing large scale structure. Prominent in the map is a Sloan Great Wall of galaxies 1.37 billion light years long, 80% longer than the Great Wall discovered by Geller and Huchra and therefore the largest observed structure in the universe. Subject headings: methods: data analysis, large-scale structure of universe

AbstractWe studied a sample of 1672 galaxies in regions where a GRB event had occurred, in order to determine if the galactic environment plays a significant role on these energetic events. The Luminosity Function distribution for these galaxies shows some interesting features. For instance, there is a decline on the Luminosity Function at Mr~ −20.5; a lack of flatness at Mr~ −14 and higher-than-expected values of Φ(Mr) for Mr < −22.5. A comparison between our data and the Void, Wall and Early galaxies Luminosity Function was performed.

Max Tegmark, Michael A. Strauss, Michael R. Blanton, Kevork Abazajian, Scott Dodelson, Havard Sandvik, Xiaomin Wang, David H. Weinberg, Idit Zehavi, Neta A. Bahcall, Fiona Hoyle, David Schlegel, Roman Scoccimarro, Michael S. Vogeley, Andreas Berlind, Tamás Budavari, Andrew Connolly, Daniel J. Eisenstein, Douglas Finkbeiner, Joshua A. Frieman, James E. Gunn, Lam Hui, Bhuvnesh Jain, David Johnston, Stephen Kent, Huan Lin, Reiko Nakajima, Robert C. Nichol, Jeremiah P. Ostriker, Adrian Pope, Ryan Scranton, Uroš Seljak, Ravi K. Sheth, Albert Stebbins, Alexander S. Szalay, István Szapudi, Yongzhong Xu, James Annis, J. Brinkmann, Scott Burles, Francisco J. Castander, Istvan Csabai, Jon Loveday, Mamoru Doi, Masataka Fukugita, Bruce Gillespie, Greg Hennessy, David W. Hogg, Željko Ivezić, Gillian R. Knapp, Don Q. Lamb, Brian C. Lee, Robert H. Lupton, Timothy A. McKay, Peter Kunszt, Jeffrey A. Munn, Liam O’Connell, John Peoples, Jeffrey R. Pier, Michael Richmond, Constance Rockosi, Donald P. Schneider, Christopher Stoughton, Douglas L. Tucker, Daniel E. Vanden Berk, Brian Yanny, Donald G. York Department of Physics, University of Pennsylvania, Philadelphia, PA 19104, USA; Dept. of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139; Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003; Princeton University Observatory, Princeton, NJ 08544, USA; Department of Physics, Drexel University, Philadelphia, PA 19104, USA; Department of Astronomy, Ohio State University, Columbus, OH 43210, USA; Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510, USA; Center for Cosmological Physics and Department of Astronomy & Astrophysics, University of Chicago, Chicago, IL 60637, USA; Department of Physics and Astronomy, The Johns Hopkins University, 3701 San Martin Drive, Baltimore, MD 21218, USA; University of Pittsburgh, Department of Physics and Astronomy, 3941 O’Hara Street, Pittsburgh, PA 15260, USA; Department of Astronomy, University of Arizona, Tucson, AZ 85721, USA; Department of Physics, 5000 Forbes Avenue, Carnegie Mellon University, Pittsburgh, PA 15213, USA; Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA; Apache Point Observatory, 2001 Apache Point Rd, Sunspot, NM 88349-0059, USA; Institut d’Estudis Espacials de Catalunya/CSIC, Gran Capita 2-4, 08034 Barcelona, Spain; Sussex Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QJ, UK; Institute of Astronomy, Univ. of Tokyo, Kashiwa 277-8582, Japan; U.S. Naval Observatory, Flagstaff Station, Flagstaff, AZ 86002-1149, USA; Dept. of Physics, Univ. of Michigan, Ann Arbor, MI 48109-1120, USA; Physics Dept., Rochester Inst. of Technology, 1 Lomb Memorial Dr, Rochester, NY 14623, USA; Dept. of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802, USA; Enrico Fermi Institute, University of Chicago, Chicago, IL 60637, USA; Theoretical Division, MS B285, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA;

We measure the star formation properties of two large samples of galaxies from the SDSS in large-scale cosmic voids on timescales of 10 and 100 Myr, using Hα emission line strengths and GALEX FUV fluxes, respectively. The first sample consists of 109,818 optically selected galaxies. We find that void galaxies in this sample have higher specific star formation rates (SSFRs; star formation rates per unit stellar mass) than similar stellar mass galaxies in denser regions. The second sample is a subset of the optically selected sample containing 8070 galaxies with reliable H i detections from ALFALFA. For the full H i detected sample, SSFRs do not vary systematically with large-scale environment. However, investigating only the H i detected dwarf galaxies reveals a trend toward higher SSFRs in voids. Furthermore, we estimate the star formation rate per unit H i mass (known as the star formation efficiency; SFE) of a galaxy, as a function of environment. For the overall H i detected population, we notice no environmental dependence. Limiting the sample to dwarf galaxies still does not reveal a statistically significant difference between SFEs in voids versus walls. These results suggest that void environments, on average, provide a nurturing environment for dwarf galaxy evolution allowing for higher specific star formation rates while forming stars with similar efficiencies to those in walls.

We present a study of spectral properties of galaxies in underdense large-scale structures, or voids. Our void galaxy sample (75,939 galaxies) is selected from the Sloan Digital Sky Survey Data Release 7 with z < 0.107. We find that there are no significant differences in the luminosities, stellar masses, stellar populations, and specific star formation rates between void galaxies of specific spectral types and their wall counterparts. However, the fraction of star-forming galaxies in voids is significantly higher (>= 9%) than that in walls. Void galaxies, when considering all spectral types, are slightly fainter, are less massive, have younger stellar populations, and have higher specific star formation rates than wall galaxies. These minor differences are totally caused by the higher fraction of star-forming galaxies in voids. We confirm that active galactic nuclei (AGNs) exist in voids, already found by Constantin et al. in 2008, with similar abundance to that in walls. Type I AGNs contribute similar to 1%-2% of void galaxies, similar to their fraction in walls. The intrinsic [O III] luminosities, spanning over 106-109L., and Eddington ratios are similar comparing our void AGNs versus wall AGNs. Small-scale statistics show that all spectral types of void galaxies are less clustered than their counterparts in walls. Major merger may not be the dominant trigger of black hole accretion in the luminosity range we probe. Our study implies that the growth of black holes relies weakly on large-scale structures.

The bridge effect of void filaments is a phrase coined by Park & Lee to explain the correlations found in a numerical experiment between the luminosity of the void galaxies and the degree of straightness of their host filaments. Their numerical finding implies that a straight void filament provides a narrow channel for the efficient transportation of gas and matter particles from the surroundings into void galaxies. Analyzing the Sloan void catalog constructed by Pan et al., we identify the filamentary structures in void regions and determine the specific size of each void filament as a measure of its straightness. To avoid possible spurious signals caused by Malmquist bias, we consider only those void filaments whose redshifts are in the range 0 <= z <= 0.02 and find a clear tendency that the void galaxies located in the straighter filaments are on average more luminous, which is in qualitative agreement with the numerical prediction. It is also shown that the strength of correlation increases with the number of member galaxies in the void filaments, which can be understood physically on the grounds that the more stretched filaments can connect the dense surroundings even to galaxies located deep in the central parts of the voids. This observational evidence may provide a key clue to the puzzling issue of why the void galaxies have higher specific star formation rates and bluer colors than their wall counterparts.

The shapes of cosmic voids are prone to distortions by the external tidal forces since their low-densities imply a lower internal resistance. This susceptibility of the void shapes to the tidal distortions makes them useful as an indicator of the large-scale tidal and density fields, despite the practical difficulty in defining them. Using the void catalog constructed by Pan et al. (2012) from the Seventh Data Release of the Sloan Digital Sky Survey (SDSS DR7), we detect a clear 4 sigma signal of spatial correlations of the void shapes on the scale of 20 Mpc/h and show that the signal is robust against the projection of the void shapes onto the plane of sky. By constructing a simple analytic model for the void shape correlation, within the framework of tidal torque theory, we demonstrate that the void shape correlation function scales linearly with the two-point correlation function of the linear density field. We also find a direct observational evidence for the cross-correlation of the void shapes with the large-scale velocity shear field that was linearly reconstructed by Lee et al. (2014) from the SDSS DR7. We discuss the possibility of using the void shape correlation function to break the degeneracy between the density parameter and the power spectrum amplitude and to independently constrain the neutrino mass as well.

We measure the r-band galaxy luminosity function (LF) across environments over the redshift range 0 < z < 0.107 using the Sloan Digital Sky Survey (SDSS). We divide our sample into galaxies residing in large-scale voids (void galaxies) and those residing in denser regions (wall galaxies). The best-fitting Schechter parameters for void galaxies are log Phi* = -3.40 +/- 0.03 log(Mpc(-3)), M* = -19.88 +/- 0.05, and alpha = -1.20 +/- 0.02. For wall galaxies, the best-fitting parameters are log Phi* = -2.86 +/- 0.02 log(Mpc(-3)), M* = -20.80 +/- 0.03, and alpha = -1.16 +/- 0.01. We find a shift in the characteristic magnitude, M*, toward fainter magnitudes for void galaxies and find no significant difference between the faint-end slopes of the void and wall galaxy LFs. We investigate how low-surface-brightness selection effects can affect the galaxy LF. To attempt to examine a sample of galaxies that is relatively free of surface-brightness selection effects, we compute the optical galaxy LF of galaxies detected by the blind H I survey Arecibo Legacy Fast ALFA (ALFALFA). We find that the global LF of the ALFALFA sample is not well fit by a Schechter function because of the presence of a wide dip in the LF around M-r = -18 and an upturn at fainter magnitudes (alpha similar to -1.47). We compare the H I selected r-band LF to various LFs of optically selected populations to determine where the H I selected optical LF obtains its shape. We find that sample selection plays a large role in determining the shape of the LF.

We measure the HI mass function (HIMF) and velocity width function (WF) across environments over a range of masses, 7.2 < log (M-HI/M-circle dot) < 10.8, and profile widths, 1.3 log (km s(-1)) < log (W) < 2.9 log (km s(-1)), using a catalogue of similar to 7300 HI-selected galaxies from the Arecibo Legacy Fast ALFA (ALFALFA) Survey, located in the region of sky where ALFALFA and Sloan Digital Sky Survey (Data Release 7) North overlap. We divide our galaxy sample into those that reside in large-scale voids (void galaxies) and those that live in denser regions (wall galaxies). We find the void HIMF to be well fitted by a Schechter function with normalization Phi* = (1.37 +/- 0.1) x 10(-2) y h(3) Mpc(-3), characteristic mass log(M-HI*/M-circle dot) + 2 log h(70) = 9.86 +/- 0.02, and low-mass-end slope alpha = -1.29 +/- 0.02. Similarly, for wall galaxies, we find best-fitting parameters Phi* = (1.82 +/- 0.03) x 10(-2) h(3) Mpc(-3), log(M-H I*/M-circle dot) + 2 log h(70) = 10.00 +/- 0.01, and alpha = -1.35 +/- 0.01. We conclude that void galaxies typically have slightly lower HI masses than their non-void counterparts, which is in agreement with the dark matter (DM) halo mass function shift in voids assuming a simple relationship between DM mass and HI mass. We also find that the low-mass slope of the void HIMF is similar to that of the wall HIMF suggesting that there is either no excess of low-mass galaxies in voids or there is an abundance of intermediate HI mass galaxies. We fit a modified Schechter function to the ALFALFA void WF and determine its best-fitting parameters to be Phi* = 0.21 +/- 0.1 h(3) Mpc(-3), log (W*) = 2.13 +/- 0.3, alpha = 0.52 +/- 0.5, and high-width slope beta = 1.3 +/- 0.4. For wall galaxies, the WF parameters are Phi* = 0.022 +/- 0.009 h(3) Mpc(-3), log (W*)= 2.62 +/- 0.5, alpha= -0.64 +/- 0.2, and beta = 3.58 +/- 1.5. Because of large uncertainties on the void and wall WFs, we cannot conclude whether the WF is dependent on the environment.

Using the sample presented in Pan:2011, we analyse the photometric properties of 88,794 void galaxies and compare them to galaxies in higher density environments with the same absolute magnitude distribution. In Pan et al. (2011), we found a total of 1054 dynamically distinct voids in the SDSS with radius larger than 10h^-1 Mpc. The voids are underdense, with delta rho/rho < -0.9 in their centers. Here we study the photometric properties of these void galaxies. We look at the u - r colours as an indication of star formation activity and the inverse concentration index as an indication of galaxy type. We find that void galaxies are statistically bluer than galaxies found in higher density environments with the same magnitude distribution. We examine the colours of the galaxies as a function of magnitude, and we fit each colour distribution with a double-Gaussian model for the red and blue subpopulations. As we move from bright to dwarf galaxies, the population of red galaxies steadily decreases and the fraction of blue galaxies increases in both voids and walls, however the fraction of blue galaxies in the voids is always higher and bluer than in the walls. We also split the void and wall galaxies into samples depending on galaxy type. We find that late type void galaxies are bluer than late type wall galaxies and the same holds for early galaxies. We also find that early type, dwarf void galaxies are blue in colour. We also study the properties of void galaxies as a function of their distance from the center of the void. We find very little variation in the properties, such as magnitude, colour and type, of void galaxies as a function of their location in the void. The only exception is that the dwarf void galaxies may live closer to the center. The centers of voids have very similar density contrast and hence all void galaxies live in very similar density environments (ABRIDGED)

We study the distribution of cosmic voids and void galaxies using Sloan Digital Sky Survey Data Release 7 (SDSS DR7). Using the VoidFinder algorithm based on the original VoidFinder method devised by El-Ad & Piran and implemented by Hoyle & Vogeley, we identify 1054 statistically significant voids in the Northern galactic hemisphere with radii >10 h(-1) Mpc. The filling factor of voids in the sample volume is 62 per cent. The largest void is just over 30 h-1 Mpc in effective radius. The median effective radius is 17 h-1 Mpc. The voids are found to be significantly underdense, with density contrast delta < -0.85 at the edges of the voids. The radial-density profiles of these voids are similar to predictions of dynamically distinct underdensities in gravitational theory. We find 8046 galaxies brighter than M-r = -20.09 within the voids, accounting for 7 per cent of the galaxies. We compare the results of VoidFinder on SDSS DR7 to mock catalogues generated from a smoothed particle hydrodynamics (SPH) halo model simulation as well as other Lambda cold dark matter (Lambda CDM) simulations and find similar void fractions and void sizes in the data and simulations. This catalogue is made publicly available at http://www.physics.drexel.edu/similar to pan/VoidCatalog for download.

We present a catalog of more than 103 void galaxies from the Sloan Digital Sky Survey. We use a nearest neighbor analysis to construct the sample of void galaxies. The density field of galaxies is traced using a volume-limited sample with zmax = 0.089. Galaxies from the flux-limited SDSS with z ≤ zmax and fewer than three volume-limited neighbors within 7h−1Mpc are classified as void galaxies. Details of how the sample of void galxies is obtained are discussed in Rojas et al. (2003). These galaxies have density contrast δρ/ρ < −0.6 and span a range of absolute magnitude from Mr = −13.5 to Mr = −22.5 with redshift z < 0.089. Measured photometric parameters from the SDSS photo pipeline include, the absolute magnitude in u, g, r, i, z, concentration index, and Sersic index. In addtion, spectroscopic parameters from the SDSS spectro1d pipeline such as the equivalent width, sigma, and height of the fitted Gaussian to the respective line are also included for 5 emission lines. Derived star formation and specific star formation rates from Hα are also included. We provide the 4000 Å Balmer strength and stellar masses from Kauffmann et al. (2003; K03a). For other galaxies in our sample not included in K03a we estimate the stellar masses from a least squares fit using the z-band flux. Color composite images and calibrated spectra of all objects are also available. Rojas et al. (2003, 2004) studied the photometric and spectroscopic properties of these galaxies and discovered that they are bluer, more late-type, have larger emission line equivalent widths, larger specific star formation rates, smaller stellar masses and smaller 4000 Å Balmer break than non-void galaxies of similar luminosities and surface brightness profiles. Hoyle et al. (2003) computed the corresponding luminosity function and found that voids are not filled with a large population of dwarf galaxies. The metallicities of these void galaxies were studied by Hao et al. (2004) and it was found that they have slightly lower metallicities than galaxies in more typical environments. Subject headings: catalogs – galaxies: large-scale structure of the universe – On-line material: machine-readable table

We present a comprehensive study of accretion activity in the most underdense environments in the universe, the voids, based on the SDSS DR2 data. Based on investigations of multiple void regions, we show that active galactic nuclei (AGNs) are definitely common in voids, but that their occurrence rate and properties differ from those in walls. AGNs are more common in voids than in walls, but only among moderately luminous and massive galaxies (Mr < − 20, log M*/M☉ < 10.5), and this enhancement is more pronounced for the relatively weak accreting systems (i.e., L[O III] < 1039 erg s−1). Void AGNs hosted by moderately massive and luminous galaxies are accreting at equal or lower rates than their wall counterparts, show lower levels of obscuration than in walls, and have similarly aged stellar populations. The very few void AGNs in massive bright hosts accrete more strongly, are more obscured, and are associated with younger stellar emission than wall AGNs. These trends suggest that the accretion strength is connected to the availability of fuel supply, and that accretion and star formation coevolve and rely on the same source of fuel. Nearest neighbor statistics indicate that the weak accretion activity (LINER-like) usually detected in massive systems is not influenced by the local environment. However, H II galaxies, Seyferts, and transition objects are preferentially found among more grouped small-scale structures, indicating that their activity is influenced by the rate at which galaxies interact with each other. These trends support a potential H II→ Seyfert/transition object→ LINER evolutionary sequence that we show is apparent in many properties of actively line-emitting galaxies, in both voids and walls. The subtle differences between void and wall AGNs might be explained by a longer, less disturbed duty cycle of these systems in voids.

The current view of galaxy formation holds that all massive galaxies harbor a massive black hole at their center, but that these black holes are not always in an actively accreting phase. X-ray emission is often used to identify accreting sources, but for galaxies that are not harboring quasars (low-luminosity active galaxies), the X-ray flux may be weak, or obscured by dust. To aid in the understanding of weakly accreting black holes in the local universe, a large sample of galaxies with X-ray detections is needed. We cross-match the ROSAT All Sky Survey (RASS) with galaxies from the Sloan Digital Sky Survey Data Release 4 (SDSS DR4) to create such a sample. Because of the high SDSS source density and large RASS positional errors, the cross-matched catalog is highly contaminated by random associations. We investigate the overlap of these surveys and provide a statistical test of the validity of RASS–SDSS galaxy cross-matches. The SDSS quasars provide a test of our cross-match validation scheme, as they have a very high fraction of true RASS matches. We find that the number of true matches between the SDSS main galaxy sample and the RASS is highly dependent on the optical spectral classification of the galaxy; essentially no star-forming galaxies are detected, while more than 0.6% of narrow-line Seyferts are detected in the RASS. Also, galaxies with ambiguous optical classification have a surprisingly high RASS detection fraction. This allows us to further constrain the SEDs of low-luminosity active galaxies. Our technique is quite general, and can be applied to any cross-matching between surveys with well-understood positional errors.

Despite a history that dates back at least a quarter of a century studies of voids in the large–scale structure of the Universe are bedevilled by a major problem: there exist a large number of quite different void–finding algorithms, a fact that has so far got in the way of groups comparing their results without worrying about whether such a comparison in fact makes sense. Because of the recent increased interest in voids, both in very large galaxy surveys and in detailed simulations of cosmic structure formation, this situation is very unfortunate. We here present the first systematic comparison study of thirteen different void finders constructed using particles, haloes, and semi–analytical model galaxies extracted from a subvolume of the Millennium simulation. The study includes many groups that have studied voids over the past decade. We show their results and discuss their differences and agreements. As it turns out, the basic results of the various methods agree very well with each other in that they all locate a major void near the centre of our volume. Voids have very underdense centres, reaching below 10 percent of the mean cosmic density. In addition, those void finders that allow for void galaxies show that those galaxies follow similar trends. For example, the overdensity of void galaxies brighter than m_B = -20 is found to be smaller than about -0.8 by all our void finding algorithms.

We present an analysis of voids in the 2dF Galaxy Redshift Survey (2dFGRS). This analysis includes identification of void regions and measurement of void statistics. The 2dFGRS is the largest completed redshift survey to date, including a total of 245,591 galaxies covering 1500 deg2 to a median depth of zmed ~ 0.11. We use the voidfinder algorithm to identify a total of 289 voids in the 2dFGRS with radius larger than 10 h-1 Mpc. These voids have an average effective radius, the radius of a sphere with the same volume as the void, of h-1 Mpc in the North Galactic Pole region (NGP) and h-1 Mpc in the South Galactic Pole region (SGP). These voids are extremely underdense, with average density contrast of δρ/ρ = -0.94 ± 0.02. The centers of voids are even emptier, because the few galaxies within the voids typically lie close to the edges. The total volume of the universe filled by these void regions is approximately 40%. These results are very similar to results found from our analysis of the PSCz survey and the Updated Zwicky Catalog; here we detect almost a factor of 10 more voids. We measure the void probability function (VPF) of the 2dFGRS for volume-limited samples with limiting absolute magnitudes, Mlim - 5 log h, from -16 to -21 in bJ. We measure the underdensity probability function (with density contrast threshold δρ/ρ = -0.8) for samples with limiting absolute magnitudes, Mlim - 5 log h, from -18 to -21. We find that the SGP is more underdense than the NGP for all but the brightest sample under consideration. There is good agreement between the VPFs of the Center for Astrophysics survey and the 2dFGRS. Comparison of VPFs measured for the 2dFGRS with the distribution of simulated dark matter halos of similar number density indicates that voids in the matter distribution in ΛCDM simulations are not empty enough. However, semianalytic models of galaxy formation that include feedback effects yield VPFs that show excellent agreement with the data.

Wide-angle, moderately deep redshift surveys such as that conducted as part of the Sloan Digital Sky Survey (SDSS) allow study of the relationship between the structural elements of the large-scale distribution of galaxies – including groups, cluster, superclusters, and voids – and the dependence of galaxy formation and evolution on these enviroments. We present a progress report on mapping efforts with the SDSS and discuss recently constructed catalogs of clusters, voids, and void galaxies, and evidence for a $420h^{-1}$Mpc supercluster or “Great Wall.” Analysis of multi-band photometry and moderate-resolution spectroscopy from the SDSS reveals environmental dependence of the star formation history of galaxies that extends over more than a factor of 100 in density, from clusters all the way to the deep interiors of voids. On average, galaxies in the rarified environments of voids exhibit bluer colors, higher specific star formation rates, lower dust content, and more disk-like morphology than objects in denser regions. This trend persists in comparisons of samples in low vs. high-density regions with similar luminosity and morphology, thus this dependence is not simply an extension of the morphology-density relation. Large-scale modulation of the halo mass function and the temperature of the intergalactic medium might explain this dependence of galaxy evolution on the large-scale environment.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

One of the most striking features in galaxy redshift surveys is the ubiquitous presence of voids. However, voids have not been extensively studied due to observational limitations. Until recently, galaxy redshift surveys included only a few voids of diameter > 30 h-1Mpc. The first step in studying voids is the identification process. We outline a method for detecting voids (based on the method of El-Ad and Piran 1997, EP97). We apply it to the PSCz survey, and the Updated Zwicky Catalog. We find that voids have typical diameters of ~30 h-1Mpc and are very underdense regions with (delta rho)/rho ~ -0.95. Up to 40% of volume of the Universe is occupied by voids. We discuss the results from these surveys and our detection algorithm's usefulness for future surveys. The next generation of surveys (such as the Sloan Digital Sky Survey and 2dFGRS) will improve this situation. The surveys will extend to greater depths, allowing a more statistically complete sample of voids to be obtained and the accompanying digital imaging will provide accurate photometry of fainter objects. This will allow us to gain greater insight into the nature of voids, search for possible void galaxies and maybe place constraints on cosmological parameters as voids play a critical role in the evolution of large scale structure.