Search Publications
Possible Detection of an Emission Cyclotron Resonance Scattering Feature from the Accretion-powered Pulsar 4U 1626-67
Mihara, T.; Tashiro, M. S.; Yamada, S. +7 more
We present analysis of 4U 1626-67, a 7.7 s pulsar in a low-mass X-ray binary system, observed with the hard X-ray detector of the Japanese X-ray satellite Suzaku in 2006 March for a net exposure of ~88 ks. The source was detected at an average 10-60 keV flux of ~4 × 10-10 erg cm-2 s-1. The phase-averaged spectrum i…
Exploring X-ray and radio emission of type 1 AGN up to z ~ 2.3
Ballo, L.; Barcons, X.; Carrera, F. J. +1 more
Context. X-ray emission from active galactic nuclei (AGN) is dominated by the accretion disk around a supermassive black hole. The radio luminosity, however, has not such a clear origin except in the most powerful sources where jets are evident. The origin (and even the very existence) of the local bi-modal distribution in radio-loudness is also a…
Herschel-PACS far-infrared detections of Lyman-α emitters at 2.0 ≲ z ≲ 3.5
Berta, S.; Magnelli, B.; Lutz, D. +23 more
In this work we analyse the physical properties of a sample of 56 spectroscopically selected star-forming (SF) Lyα emitting galaxies at 2.0 ≲ z ≲ 3.5 using both a spectral energy distribution (SED) fitting procedure from rest-frame UV to mid-IR and direct 160 µm FIR observations taken with the Photodetector Array Camera and Spectrometer (PAC…
Probing the M_BH-σ* Relation in the Non-local Universe Using Red QSOs
Lacy, Mark; Canalizo, Gabriela; Hiner, Kyle D. +3 more
We describe a method to measure the M_BH-σ* relation in the non-local universe using dust-obscured QSOs. We present results from a pilot sample of nine Two Micron All Sky Survey red QSOs with redshifts 0.14 < z < 0.37. We find that there is an offset (0.8 dex, on average) between the position of our objects and the local relation …
Late-time Light Curves of Type II Supernovae: Physical Properties of Supernovae and Their Environment
Barlow, Michael J.; Panagia, Nino; Meixner, Margaret +9 more
We present BVRIJHK-band photometry of six core-collapse supernovae, SNe 1999bw, 2002hh, 2003gd, 2004et, 2005cs, and 2006bc, measured at late epochs (>2 yr) based on the Hubble Space Telescope (HST), and the Gemini North, and WIYN telescopes. We also show the JHK light curves of supernova impostor SN 2008S up to day 575 because it was serendipit…
On Molecular Hydrogen Formation and the Magnetohydrostatic Equilibrium of Sunspots
Lin, H.; Jaeggli, S. A.; Uitenbroek, H.
We have investigated the problem of sunspot magnetohydrostatic equilibrium with comprehensive IR sunspot magnetic field survey observations of the highly sensitive Fe I lines at 15650 Å and nearby OH lines. We have found that some sunspots show isothermal increases in umbral magnetic field strength which cannot be explained by the simplified sunsp…
XMM-Newton observation of the persistent Be/NS X-ray binary pulsar RX J0440.9+4431
Tiengo, A.; Mereghetti, S.; Sidoli, L. +2 more
Many X-ray accreting pulsars have a soft excess below 10 keV. This feature was also detected in faint sources and at low luminosity levels, suggesting that it is an ubiquitous phenomenon. For the high luminosity pulsars (LX > 1036 erg s-1), the fit to this component with thermal emission models usually provides …
Thermal and Chemical Structure Variations in Titan's Stratosphere during the Cassini Mission
Teanby, N. A.; Flasar, F. M.; Preka-Papadema, P. +12 more
We have developed a line-by-line Atmospheric Radiative Transfer for Titan code that includes the most recent laboratory spectroscopic data and haze descriptions relative to Titan's stratosphere. We use this code to model Cassini Composite Infrared Spectrometer data taken during the numerous Titan flybys from 2006 to 2012 at surface-intercepting ge…
An Interpretation of the Possible Mechanisms of Two Ground-level Enhancement Events
Gan, W. Q.; Moon, Y. -J.; Firoz, Kazi A. +1 more
We have carried out this work to clarify the possible mechanisms of two important high-energy particle events (GLE69 2005 January 20, 06:46 UT and GLE70 2006 December 13, 02:45 UT). For this purpose, the cosmic-ray intensities registered by neutron monitors at several sites have been analyzed and studied with concurrent solar flares of different e…
HESS observations of the Carina nebula and its enigmatic colliding wind binary Eta Carinae
Klochkov, D.; Santangelo, A.; Quirrenbach, A. +191 more
The massive binary system Eta Carinae and the surrounding H II complex, the Carina nebula, are potential particle acceleration sites from which very high energy (VHE; E≥ 100 GeV) γ-ray emission could be expected. This paper presents data collected during VHE γ-ray observations with the HESS telescope array from 2004 to 2010, which cover a full orb…