We present spectroscopic observations for a sample of 36 Herschel-Spire 250-500 mu m selected galaxies (HSGs) at 2 \textless z \textless 5 from the Herschel Multi-tiered Extragalactic Survey. ...Redshifts are confirmed as part of a large redshift survey of Herschel-Spire-selected sources covering similar to 0.93 deg(2) in six extragalactic legacy fields. Observations were taken with the Keck I Low Resolution Imaging Spectrometer and the Keck II DEep Imaging Multi-Object Spectrograph. Precise astrometry, needed for spectroscopic follow-up, is determined by identification of counterparts at 24 mu m or 1.4 GHz using a cross-identification likelihood matching method. Individual source luminosities range from log(L-IR/L-circle dot) = 12.5-13.6 (corresponding to star formation rates (SFRs) 500-9000M(circle dot) yr(-1), assuming a Salpeter initial mass function), constituting some of the most intrinsically luminous, distant infrared galaxies discovered thus far. We present both individual and composite rest-frame ultraviolet spectra and infrared spectral energy distributions. The selection of these HSGs is reproducible and well characterized across large areas of the sky in contrast to most z \textgreater 2 HyLIRGs in the literature, which are detected serendipitously or via tailored surveys searching only for high-z HyLIRGs; therefore, we can place lower limits on the contribution of HSGs to the cosmic star formation rate density (SFRD) at (7 +/- 2) x 10(-3) M-circle dot yr(-1) h(3) Mpc(-3) at z similar to 2.5, which is \textgreater 10% of the estimated total SFRD of the universe from optical surveys. The contribution at z similar to 4 has a lower limit of 3 x 10(-3) M-circle dot yr(-1) h(3) Mpc(-3), greater than or similar to 20% of the estimated total SFRD. This highlights the importance of extremely infrared-luminous galaxies with high SFRs to the buildup of stellar mass, even at the earliest epochs.
ABSTRACT For the first time, we investigate the X-ray/infrared (IR) correlation for star-forming galaxies (SFGs) at z 1, using SPIRE submm data from the recently launched Herschel Space Observatory ...and deep X-ray data from the 2-Ms Chandra Deep Field-North survey. We examine the X-ray/IR correlation in the soft X-ray (SX; 0.5-2keV) and hard X-ray (HX; 2-10keV) bands by comparing our z 1 SPIRE-detected SFGs to equivalently IR-luminous (LIR > 1010L) samples in the local/low-redshift Universe. Our results suggest that the X-ray/IR properties of the SPIRE SFGs are on average similar to those of their local counterparts, as we find no evidence for evolution in the LSX/LIR and LHX/LIR ratios with redshift. We note, however, that at all redshifts, both LSX/LIR and LHX/LIR are strongly dependent on IR luminosity, with luminous and ultraluminous IR galaxies (LIRGs and ULIRGs; LIR > 1011L) having up to an order of magnitude lower values than normal IR galaxies (LIR < 1011L). We derive a LSX-LIR relation and confirm the applicability of an existing LHX-LIR relation for both local and distant LIRGs and ULIRGs, consistent with a scenario where X-ray luminosity is correlated with the star formation rate. PUBLICATION ABSTRACT
Angiotensin II (Ang II) and its transmembrane AT
1
receptor were selected in order to test an innovative strategy that might allow the assessment of the agonist binding site in the receptor molecule. ...With the use of the 2,2,6,6-tetramethylpiperidine-1-oxyl-4-amino-4-carboxylic acid (TOAC) paramagnetic probe, a biologically active agonist (TOAC
1
-Ang II), as well as an inactive control (TOAC
4
-Ang II) analogs were mixed in solution with various synthesized AT
1
fragments. Comparative intermolecular interactions, as estimated by analyzing the EPR spectra of solutions, suggested the existence of an agonist binding site containing a sequence composed of portions of the N-terminal (13-17) and the third extracellular loop (266-278) fragments of the AT
1
molecule. Therefore, this combined EPR-TOAC approach shows promise as an alternative for use also in other applications related to specific intermolecular association processes.
The extragalactic background light at far-infrared wavelengths comes from optically faint, dusty, star-forming galaxies in the Universe with star formation rates of a few hundred solar masses per ...year. These faint, submillimetre galaxies are challenging to study individually because of the relatively poor spatial resolution of far-infrared telescopes. Instead, their average properties can be studied using statistics such as the angular power spectrum of the background intensity variations. A previous attempt at measuring this power spectrum resulted in the suggestion that the clustering amplitude is below the level computed with a simple ansatz based on a halo model. Here we report excess clustering over the linear prediction at arcminute angular scales in the power spectrum of brightness fluctuations at 250, 350 and 500 µm. From this excess, we find that submillimetre galaxies are located in dark matter haloes with a minimum mass, M^sub min^, such that ... at 350 µm, where ... is the solar mass. This minimum dark matter halo mass corresponds to the most efficient mass scale for star formation in the Universe, and is lower than that predicted by semi-analytical models for galaxy formation. PUBLICATION ABSTRACT
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