arXiv:0810.1229 [ps, pdf, other] Title: The cluster-galaxy cross-spectrum: an additional probe of cosmological and halo parameters Authors: Gert Huetsi, Ofer Lahav Comments: 12 pages, Accepted for publication in A&A Subjects: Astrophysics (astro-ph) There are several wide field galaxy and cluster surveys planned for the nearest future, e.g. BOSS, WFMOS, ADEPT, Hetdex, SPT, eROSITA. In the simplest approach one would analyze these independently, thus neglecting the extra information provided by the cluster-galaxy cross-pairs. In this paper we have focused on the possible synergy between these surveys by investigating the amount of information encoded in the cross-pairs. We present a model for the cluster-galaxy cross-spectrum within the Halo Model framework. To assess the gain in performance due to inclusion of the cluster-galaxy cross-pairs we carry out a Fisher matrix analysis for a BOSS-like galaxy redshift survey targeting luminous red galaxies and a hypothetical mass-limited cluster redshift survey with a lower mass threshold of 1.7x10^14 M_sun/h over the same volume. On small scales cluster-galaxy cross-spectrum probes directly density profile of the halos, instead of the density profile convolved with itself, as is the case for the galaxy power spectrum. Due to this different behavior, adding information from the cross-pairs helps to tighten constraints on the halo occupation distribution. By inclusion of the cross-pairs a factor of ~2 stronger constraints are obtained for sigma_8, while the improvement for the dark energy figure-of-merit is somewhat weaker: an increase by a factor of 1.4. arXiv:0810.1283 [pdf, other] Title: The GALFA-HI Survey: Techniques Authors: J. E. G. Peek, Carl Heiles Comments: 25 pages, 10 figures Subjects: Astrophysics (astro-ph) We explain the entire process by which we conduct the Galactic Arecibo L-Band Feed Array HI (GALFA-HI) survey. The survey is a high resolution (3.4'), large area (13000 deg^2), large Galactic velocity range (-750 to +750 km/s), high spectral resolution (0.18 km/s) survey of the Galaxy in the 21 cm line hyperfine transition of hydrogen conducted at Arecibo Observatory. We touch on some of the new Galactic science being conducted using the GALFA-HI survey, ranging from High-Velocity Clouds to HI narrow-line self-absorption. We explain the many technical challenges that confront such a survey, including baseline ripple, gain variation and asymmetrical beam shapes. To correct for these systematic effects we use various newly developed methods, which we describe in detail. We also explain the data reduction process step by step, starting with the raw time-ordered data and ending with fully calibrated maps. The effects of each step of the data reduction on the final data product is shown sequentially. We conclude with future directions for the ongoing survey. arXiv:0810.1471 [pdf] Title: The formation and assembly of a typical star-forming galaxy at z~3 Authors: Daniel P. Stark, Mark Swinbank, Richard S. Ellis, Simon Dye, Ian R. Smail, Johan Richard Comments: To appear in Nature, Vol 455, Oct 9 2008 Subjects: Astrophysics (astro-ph) Recent studies of galaxies ~2-3 Gyr after the Big Bang have revealed large, turbulent rotating systems. The existence of well-ordered rotation in galaxies during this peak epoch of cosmic star formation may suggest that gas accretion through cold streams is likely to be the dominant mode by which most star-forming galaxies at high redshift since major mergers can completely disrupt the observed velocity fields. However poor spatial resolution and sensitivity have hampered this interpretation, limiting the study to the largest and most luminous galaxies, which may have fundamentally different modes of assembly than more typical star forming galaxies. Here we report observations of a typical star forming galaxy at z=3.07 with a linear resolution of ~100 parsec. This spatial sampling is made possible by the combination of gravitational lensing and laser guide star adaptive optics. We find a well-ordered compact source in which molecular gas is being converted efficiently into stars, likely assembling a spheroidal bulge and disk similar to those seen in spiral galaxies at the present day. arXiv:0810.1681 [ps, pdf, other] Title: Structure and Formation of Elliptical and Spheroidal Galaxies Authors: John Kormendy, David B. Fisher, Mark E. Cornell, Ralf Bender Comments: 94 pages, 77 figures from 170 Postscript files; requires emulateapj.sty, apjfonts.sty, and psfig.sty; accepted for publication in ApJS; for a version with full resolution figures, see this http URL Subjects: Astrophysics (astro-ph) New surface photometry of all known elliptical galaxies in the Virgo cluster is added to published data to derive composite profiles over large dynamic ranges. Sersic functions fit them remarkably well. Effective brightnesses and radii are derived via Sersic fits and by integrating the profiles nonparametrically. We strongly confirm two dichotomies: (1) Elliptical galaxies from cDs to M32 form a tight sequence in Fundamental Plane parameter space that is almost perpendicular to the sequence of spheroidal galaxies from NGC 205 to Draco. This is consistent with our understanding of their different formation processes: mergers for Es and conversion of late-type galaxies into spheroidals by environmental effects and by energy feedback from supernovae. (2) Ellipticals come in two varieties: e.g., our 10 brightest Es have cuspy cores; our 17 fainter Es do not have cores. We find a new distinct component in coreless Es. All have extra light at the center above the inward extrapolation of the outer Sersic profile. We suggest that extra light is made by starbursts in dissipational (wet) mergers, as in numerical simulations. Three other new aspects also point to an explanation of how the E-E dichotomy formed: extra light Es were made in wet mergers while core Es were made in dry mergers. We confirm that core Es do and extra light Es generally do not contain X-ray gas. This suggests why the E-E dichotomy arose. Only core Es and their progenitors are massive enough to retain hot gas that can make dry mergers dry and protect old star populations from late star formation.