We report the bivariate $\rm HI$ - and $\rm H_{2}$ -stellar mass distributions of local galaxies in addition of an inventory of galaxy mass functions, MFs, for $\rm HI$ , $\rm H_{2}$ , cold gas, and baryonic mass, separately into early- and late-type galaxies. The MFs are determined using the $\rm HI$ and $\rm H_{2}$ conditional distributions and the galaxy stellar mass function (GSMF). For the conditional distributions we use the results from the compilation presented in Calette et al. [(2018) RMxAA, 54, 443.]. For determining the GSMF from $M_{*}\sim3\times10^{7}$ to $3\times10^{12}\ \text{M}_{\odot}$ , we combine two spectroscopic samples from the Sloan Digital Sky Survey at the redshift range $0.0033<z<0.2$ . We find that the low-mass end slope of the GSMF, after correcting from surface brightness incompleteness, is $\alpha\approx-1.4$ , consistent with previous determinations. The obtained $\rm HI\,$ MFs agree with radio blind surveys. Similarly, the $\rm H_{2}\,$ MFs are consistent with CO follow-up optically-selected samples. We estimate the impact of systematics due to mass-to-light ratios and find that our MFs are robust against systematic errors. We deconvolve our MFs from random errors to obtain the intrinsic MFs. Using the MFs, we calculate cosmic density parameters of all the baryonic components. Baryons locked inside galaxies represent 5.4% of the universal baryon content, while $\sim\! 96\%$ of the $\rm HI$ and $\rm H_{2}$ mass inside galaxies reside in late-type morphologies. Our results imply cosmic depletion times of $\rm H_{2}$ and total neutral H in late-type galaxies of $\sim\!1.3$ and 7.2 Gyr, respectively, which shows that late type galaxies are on average inefficient in converting $\rm H_{2}$ into stars and in transforming $\rm HI$ gas into $\rm H_{2}$ . Our results provide a fully self-consistent empirical description of galaxy demographics in terms of the bivariate gas–stellar mass distribution and their projections, the MFs. This description is ideal to compare and/or to constrain galaxy formation models.

Several extragalactic HI surveys using a λ21 cm 13-beam focal plane array will begin in early 1997 using the Parkes 64 m telescope. These surveys are designed to detect efficiently nearby galaxies that have failed to be identified optically because of low optical surface brightness or high optical extinction. We discuss scientific and technical aspects of the multibeam receiver, including astronomical objectives, feed, receiver and correlator design and data acquisition. A comparison with other telescopes shows that the Parkes multibeam receiver has significant speed advantages for any large-area λ21 cm galaxy survey in the velocity range range 0–14000 km s−1.

Recent neutral hydrogen (HI) surveys have detected enough sources to make initial predictions of the extragalactic HI luminosity function. These surveys provide useful pointers for the Parkes Multibeam Survey, highlighting various advantages and disadvantages of different observing and analysis procedures. The newest surveys are also large enough to permit some statistical tests of their completeness. The detection rates clearly fall short of what would be expected based on a simple propagation of errors, suggesting the need for further development of detection software. I suggest several procedures for determining the effective sensitivity of HI surveys. Applied to two recent Arecibo surveys, these suggest that the HI luminosity function may be much steeper than its optical counterpart, and that the Parkes surveys may detect a large number of low-mass sources.

The history of the formation of galaxies must leave an imprint in the properties of the mass function of collapsed objects and in its observational manifestation, the galaxy luminosity function. At present the faint end of the luminosity function is poorly known. Accurate knowledge of the luminosity function over the full range of galaxy clustering scales would provide serious constraints on both initial cosmological conditions and modulating astrophysical processes.

Wide field imaging surveys with large ground-based telescopes now provide the capability to identify dwarf galaxy candidates to very faint levels (μR ≈ 26 mag arcsec–2), too low in surface brightness for spectroscopy (measuring redshifts) even with telescopes like Keck. Other means have to be explored to get distance information for these candidates in order to separate cluster members from back/foreground systems beyond doubt. On the quest to establish the properties (slope and possible turning point) of the the faint end of the galaxy luminosity function we are employing the surface brightness fluctuation (SBF) method to determine adequate distances, potentially resulting in the best definition ever of the luminosity function to MR ≈ –11 in the cluster and group environments.

We report on a preliminary analysis of a 5600 sec per point survey of 32 square degrees in Centaurus, carried out with the Parkes 13-beam system. The signal-to-noise ratio is found to improve as for the whole integration. We have detected 102 HI sources between +250 and +12,700 km s−1 either by eye or by using the new galaxy-finding algorithm PICASSO. Over half of these are new HI detections. Around a dozen of these are not associated with catalogued galaxies and, in two of these cases, we have not identified an optical counterpart on the Digitized Sky Survey. Arguments are put forward to explain why deep integrations are needed to find low surface brightness objects.

We 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.

The HI Parkes All Sky Survey (HIPASS) is a blind search for extragalactic neutral hydrogen, covering the whole of the southern sky. We present the latest HI mass function (HIMF) constructed from a sample of 263 galaxies with declinations <−62°. Standard Σ1/Vmax and maximum likelihood techniques are used in the analysis. No upturn in the low-mass end of the HIMF is yet seen, though our selection procedure presently conspires against the lowest-mass galaxies.

With the advent of large-scale surveys (i.e. Legacy Surveys) it is now possible to start looking beyond the galaxy luminosity function (LF) to more detailed statistical representations of the galaxy population, i.e multivariate distributions. In this review I first summarise the current state-of-play of the B-band global and cluster LFs and then briefly present two promising bivariate distributions: the luminosity–surface brightness plane (LSP) and the colour–luminosity plane (CLP). In both planes galaxy bulges and galaxy disks form marginally overlapping but distinct distributions, indicating two key formation/evolutionary processes (presumably merger and accretion). Forward progress in this subject now requires the routine application of reliable bulge–disk decomposition codes to allow independent investigation of these two key components.

Some recent observations seem to disagree with hierarchical theories of galaxy formation on the role of major mergers in a late build-up of massive early-type galaxies. We re-address this question by analysing the morphology, structural distortion level, and star formation enhancement of a sample of massive galaxies (M* > 5 × 1010M⊙) lying on the Red Sequence and its surroundings at 0.3 < z < 1.5. We have used an initial sample of ~1800 sources with Ks < 20.5 mag over an area ~155 arcmin2 on the Groth Strip, combining data from the Rainbow Extragalactic Database and the GOYA Survey. Red galaxy classes that can be directly associated to intermediate stages of major mergers and to their final products have been defined. For the first time we report observationally the existence of a dominant evolutionary path among massive red galaxies at 0.6 < z < 1.5, consisting in the conversion of irregular disks into irregular spheroids, and of these ones into regular spheroids. This result points to: 1) the massive red regular galaxies at low redshifts derive from the irregular ones populating the Red Sequence and its neighbourhood at earlier epochs up to z ~ 1.5; 2) the progenitors of the bulk of present-day massive red regular galaxies have been blue disks that have migrated to the Red Sequence majoritarily through major mergers at 0.6 < z < 1.2 (these mergers thus starting at z ~ 1.5); 3) the formation of E-S0's that end up with M* > 1011M⊙ at z = 0 through gas-rich major mergers has frozen since z ~ 0.6. Our results support that major mergers have played the dominant role in the definitive build-up of present-day E-S0's with M* > 1011M⊙ at 0.6 < z < 1.2, in good agreement with the hierarchical scenario proposed in the Eliche-Moral et al. (2010a) model (see also Eliche-Moral et al. 2010b). This study is published in Prieto et al. (2012).

Supported by the Spanish Ministry of Science and Innovation (MICINN) under projects AYA2009-10368, AYA2006-12955, AYA2010-21887-C04-04, and AYA2009-11137, by the Madrid Regional Government through the AstroMadrid Project (CAM S2009/ESP-1496), and by the Spanish MICINN under the Consolider-Ingenio 2010 Program grant CSD2006-00070: “First Science with the GTC” (http://www.iac.es/consolider-ingenio-gtc/). S. D. H. & G.

I present mass functions of actively accreting black holes detected in different quasar surveys which in concert cover a wide range of cosmic history. I briefly address what we learn from these mass functions. I summarize the motivation for such a study and the methods by which we determine black hole masses.

We present the first estimate of the black hole mass function (BHMF) of broad-line quasars (BLQSOs) that self-consistently corrects for incompleteness and the statistical uncertainty in the mass estimates, based on a sample of 9886 quasars at 1 < z < 4.5 drawn from the Sloan Digital Sky Survey. We find evidence for “cosmic downsizing” of black holes in BLQSOs, where the peak in their number density shifts to higher redshift with increasing black hole mass. We estimate the lifetime of the BLQSO phase to be 70 ± 5 Myr for supermassive black holes (SMBHs) at z = 1 with a mass of MBH = 109M⊙, and we constrain the maximum mass of a black hole in a BLQSO to be ~ 1010M⊙. We find that most BLQSOs are not radiating at or near the Eddington limit. Our results are consistent with models for self-regulated black hole growth, where the BLQSO phase occurs at the end of a fueling event when black hole feedback unbinds the accreting gas.

The Arecibo Legacy Fast ALFA (ALFALFA) survey is a second generation blind extragalactic HI survey currently in progess which is exploiting Arecibo's superior sensitivity, angular resolution and digital technology to derive a census of the local HI universe over a cosmologically significant volume. As of the time of this meeting, some 4500 good quality extragalactic HI line sources have been identified in about 15% of the final survey area. ALFALFA is detecting HI masses as low as 106M⊙ and as large as 1010.8M⊙ with positional accuracies typically better than 20″, allowing immediate identification of the most probable optical counterparts. Only 3% of all extragalactic HI sources and less than 1% of detections with MH I > 109.5M⊙ cannot be identified with a stellar component. Because ALFALFA is far from complete, the discussion here focuses on limitations of past surveys that ALFALFA will overcome because of its greater volume, sensitivity and reduced susceptibility to source confusion and on a sampling of illustrative preliminary results. First ALFALFA results already suggest, in agreement with previous studies, that there does not appear to be a cosmologically significant population of optically dark but HI rich galaxies. ALFALFA promises a wealthy dataset for the exploration of many issues in near-field cosmology and galaxy evolution studies, setting the stage for their extension to higher redshifts in the future with the Square Kilometer Array (SKA).

For the last 25 years, the 21 cm line has been used productively to investigate the large–scale structure of the Universe, its peculiar velocity field and the measurement of cosmic parameters. In February 2005 a blind HI survey that will cover 7074 square degrees of the high latitude sky was started at Arecibo, using the 7-beam feed L-band feed array (ALFA). Known as the Arecibo Legacy Fast ALFA (ALFALFA) Survey, the program is producing a census of HI-bearing objects over a cosmologically significant volume of the local Universe. With respect to previous blind HI surveys, ALFALFA offers an improvement of about one order of magnitude in sensitivity, 4 times the angular resolution, 3 times the spectral resolution, and 1.6 times the total bandwidth of HIPASS. ALFALFA can detect 7×104D2M⊙ of HI, where D is the source distance in Mpc. As of mid 2007, 44% of the survey observations and 15% of the source extraction are completed. We discuss the status of the survey and present a few preliminary results, in particular with reference to the proposed “dark galaxy” VirgoHI21.

The location of two nearby galaxy groups within ~20 Mpc in the Leo region allows for a detailed study of low-mass galaxies. A catalog of HI line detections in Leo (9h36m < α < 11h36m, +8° < δ < +16°) has been made from the blind HI survey ALFALFA. More sensitive single-pixel Arecibo observations targeted Leo dwarf candidates noted optically by Karachentsev et al. 2004 (K04) to determine group members and allow for a comparison of HI and optically-selected samples. This presentation highlights the differences between the two samples and the significant contribution blind HI surveys can make to the missing satellites problem.

I review the history of blind HI surveys and the evidence for cosmic variance in the HI mass function. Even the most sensitive current surveys are challenged by noise levels that make determining the shape of the mass function difficult, and this can lead to discrepant results. However, some differences in the mass function appear to be real environmental effects, and this suggest that there are locales where dark (or dim) HI-rich galaxies are more likely to be found. The requirements for significantly deeper surveys beyond the local supercluster to sample cosmic variance in a wider variety of environoments are modeled and discussed.