A comprehensive view of a strongly lensed planck-associated submillimeter galaxy
Astrophysical Journal 753:2 (2012)
Abstract:
We present high-resolution maps of stars, dust, and molecular gas in a strongly lensed submillimeter galaxy (SMG) at z = 3.259. HATLAS J114637.9-001132 is selected from the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) as a strong lens candidate mainly based on its unusually high 500 μm flux density (300mJy). It is the only high-redshift Planck detection in the 130deg2 H-ATLAS Phase-I area. Keck Adaptive Optics images reveal a quadruply imaged galaxy in the K band while the Submillimeter Array and the Jansky Very Large Array show doubly imaged 880 μm and CO(1→0) sources, indicating differentiated distributions of the various components in the galaxy. In the source plane, the stars reside in three major kpc-scale clumps extended over 1.6kpc, the dust in a compact (∼1 kpc) region ∼3kpc north of the stars, and the cold molecular gas in an extended (∼7kpc) disk ∼5kpc northeast of the stars. The emissions from the stars, dust, and gas are magnified by ∼17, ∼8, and ∼7times, respectively, by four lensing galaxies at z ∼1. Intrinsically, the lensed galaxy is a warm (T dust ∼40-65 K), hyper-luminous (L IR ∼ 1.7 × 1013 L star formation rate (SFR) ∼2000 M yr-1), gas-rich (M gas/M baryon 70%), young (M stellar/SFR 20Myr), and short-lived (M gas/SFR 40Myr) starburst. With physical properties similar to unlensed z > 2 SMGs, HATLAS J114637.9-001132 offers a detailed view of a typical SMG through a powerful cosmic microscope. © 2012. The American Astronomical Society. All rights reserved..Supernova simulations and strategies for the dark energy survey
Astrophysical Journal 753:2 (2012)
Abstract:
We present an analysis of supernova light curves simulated for the upcoming Dark Energy Survey (DES) supernova search. The simulations employ a code suite that generates and fits realistic light curves in order to obtain distance modulus/redshift pairs that are passed to a cosmology fitter. We investigated several different survey strategies including field selection, supernova selection biases, and photometric redshift measurements. Using the results of this study, we chose a 30deg2 search area in the griz filter set. We forecast (1) that this survey will provide a homogeneous sample of up to 4000 TypeIa supernovae in the redshift range 0.05Multiwavelength campaign on Mrk 509: Reverberation of the Fe Kalpha line
(2012)
Observations of transients and pulsars with LOFAR international stations
ArXiv 1207.0354 (2012)
Abstract:
The LOw FRequency ARray - LOFAR is a new radio telescope that is moving the science of radio pulsars and transients into a new phase. Its design places emphasis on digital hardware and flexible software instead of mechanical solutions. LOFAR observes at radio frequencies between 10 and 240 MHz where radio pulsars and many transients are expected to be brightest. Radio frequency signals emitted from these objects allow us to study the intrinsic pulsar emission and phenomena such as propagation effects through the interstellar medium. The design of LOFAR allows independent use of its stations to conduct observations of known bright objects, or wide field monitoring of transient events. One such combined software/hardware solution is called the Advanced Radio Transient Event Monitor and Identification System (ARTEMIS). It is a backend for both targeted observations and real-time searches for millisecond radio transients which uses Graphical Processing Unit (GPU) technology to remove interstellar dispersion and detect millisecond radio bursts from astronomical sources in real-time using a single LOFAR station.Wide-band simultaneous observations of pulsars: Disentangling dispersion measure and profile variations
Astronomy and Astrophysics 543 (2012)