GMOS Spectroscopy of SCUBA Galaxies Behind A851

We have identified counterparts to two submillimeter (submm) sources, SMM J09429+4659 and SMM J09431+4700, seen through the core of the z=0.41 cluster Abell 851. We employ deep 1.4-GHz observations and the far-infrared/radio correlation to refine the submm positions and then optical and near-infrared imaging to locate their counterparts. We identify an extremely red counterpart to SMM J09429+4659, while GMOS spectroscopy with Gemini-North shows that the R=23.8 radio source identified with SMM J09431+4700 is a hyperluminous infrared galaxy (L_FIR~1.5x10^13 L_sun) at z=3.35, the highest spectroscopic redshift so far for a galaxy discovered in the submm. The emission line properties of this galaxy are characteristic of a narrow-line Seyfert-1, although the lack of detected X-ray emission in a deep XMM-Newton observation suggests that the bulk of the luminosity of this galaxy is derived from massive star formation. We suggest that active nuclei, and the outflows they engender, may be an important part of the evolution of the brightest submm galaxies at high redshifts.Comment: to appear in the Oct 1 issue of ApJ Letter

1928-29: Abilene Christian College Bible Lectures - Full Text

INTRODUCTION It has been the custom of Abilene Christian College for several years to hold an annual “Lectureship” the last week in February. This is a time of gathering of brethren from all over the state and adjoining states. It is a time of a great spiritual feast. It affords an opportunity for brethren to meet and talk over the work of the Lord. It also enables us to hear again great men of God whose voices have sounded the Word of the Lord in the days of the past in great meetings. In order that those who are not permitted to hear the lectures may enjoy them it has been the custom of Abilene Christian College to publish the lectures in a book at the end of each two years. We feel that these wonderful messages from some of the greatest minds of the church ought to be preserved that they may do good even after the lips of the speakers have become silent. It is with a prayer that great good may come that this volume of lectures of 1928 and 1929 is sent forth. We regret that some of the lectures could not be included in the book. Several of the brethren neglected to send in their manuscripts; some other manuscripts were destroyed by fire, and the brethren did not replace them. Most\u27 of the lectures are in the book. BATSELL BAXTER. DELIVERED IN THE AUDITORIUM OF ABILENE CHRISTIAN COLLEGE ABILENE, TEXAS FEBRUARY 1928-1929 FIRM FOUNDATION PUBLISHING HOUSE 104-106-108 E. 9th Street Austin, Texas

Redshift evolution of the 1.4 GHz volume averaged radio luminosity function in clusters of galaxies

By cross-correlating large samples of galaxy clusters with publicly available radio source catalogs, we construct the volume-averaged radio luminosity function (RLF) in clusters of galaxies, and investigate its dependence on cluster redshift and mass. In addition, we determine the correlation between the cluster mass and the radio luminosity of the brightest source within 50 kpc from the cluster center. We use two cluster samples: the optically selected maxBCG cluster catalog and a composite sample of X-ray selected clusters. The radio data come from the VLA NVSS and FIRST surveys. We use scaling relations to estimate cluster masses and radii to get robust estimates of cluster volumes. We determine the projected radial distribution of sources, for which we find no dependence on luminosity or cluster mass. Background and foreground sources are statistically accounted for, and we account for confusion of radio sources by adaptively degrading the resolution of the radio source surveys. We determine the redshift evolution of the RLF under the assumption that its overall shape does not change with redshift. Our results are consistent with a pure luminosity evolution of the RLF in the range 0.1 < z < 0.3 from the optical cluster sample. The X-ray sample extends to higher redshift and yields results also consistent with a pure luminosity evolution. We find no direct evidence of a dependence of the RLF on cluster mass from the present data, although the data are consistent with the most luminous sources only being found in high-mass systems.Comment: Accepted for publication in A&

An Unusual Radio Galaxy in Abell 428: A Large, Powerful FR I Source in a Disk-Dominated Host

We report the discovery of a powerful (~10^{24} Watts/Hz) FR I radio source in a highly flattened disk-dominated galaxy. Half of the radio flux from this source is concentrated within the host galaxy, with the remainder in a pair of nearly symmetrical lobes with total extent ~200kpc nearly perpendicular to the disk. The traditional wisdom maintains that powerful, extended radio sources are found only in ellipticals or recent merger events. We report B,R,J, and K imaging, optical spectroscopy, a rotation curve, an IRAS detection, and a VLA 20cm image for this galaxy, 0313-192. The optical and NIR images clearly show a disk. We detect apparent spiral arms and a dust-lane from B band imaging. The reddened nucleus is consistent with extinction by a similar dust-lane. The optical spectrum suggests a central AGN and some evidence of a starburst, with both the AGN and central starlight appearing substantially reddened. From analysis of the extended line emission in [OIII] and H-alpha we derive a rotation curve consistent with an early- type, dusty spiral seen edge-on. From the IRAS detection at 60 and 100 microns, we find that the ratio of Far IR to radio flux places this object firmly as a radio galaxy (i.e. the radio emission is not powered by star formation). The radio structure suggests that the radio source in this galaxy is related to the same physical mechanisms present in jet-fed powerful radio sources, and that such powerful, extended sources can (albeit extremely rarely) occur in a disk-dominated host.Comment: 30 pages LaTeX, 1 table, 8 postscript figures. Accepted for publication in the Astrophysical Journa

Galaxy cluster formation from the large-scale structure: a case study of the Abell 2125 complex at z=0.247

The structure of the universe is believed to have formed by clustering hierarchically from small to large scales. Much of this evolution occurs very slowly but at a few special times more rapid, violent activity may occur as major subunits collide at high velocities. The Abell 2125 complex ($z=0.247$) appears to be undergoing such an event as shown by modeling of the optical velocity field and by the detection with the VLA of an unusually large number of associated radio active galaxies. We present an 80 ksec Chandra imaging of Abell 2125, together with extensive complementary multi-wavelength data. We show direct evidence for galaxy transformation and destruction during the cluster formation. The Chandra data unambiguously separate the X-ray contributions from discrete sources and large-scale diffuse gas in the Abell 2125 complex, which consists of various merging clusters/groups of galaxies and low-surface brightness emission. This enables us to study processes affecting galaxy evolution during this special time from scales of Mpc down to a few kpc. The overall level of activity plus the special time for the cluster-cluster merger suggests that an important phase of galaxy evolution can take place during such events