Search Publications
Evidence Against an Edge-on Disk Around the Extrasolar Planet, 2MASS 1207 b and a New Thick-cloud Explanation for Its Underluminosity
Pascucci, Ilaria; Apai, Dániel; Biller, Beth A. +3 more
Since the discovery of the first directly imaged, planetary-mass object, 2MASS 1207 b, several works have sought to explain a disparity between its observed temperature and luminosity. Given its known age, distance, and spectral type, 2MASS 1207 b is underluminous by a factor of ~10 (~2.5 mag) when compared to standard models of brown-dwarf/giant-…
PTF10nvg: An Outbursting Class I Protostar in the Pelican/North American Nebula
Filippenko, Alexei V.; Cenko, S. Bradley; Law, Nicholas M. +28 more
During a synoptic survey of the North American Nebula region, the Palomar Transient Factory (PTF) detected an optical outburst (dubbed PTF10nvg) associated with the previously unstudied flat or rising spectrum infrared source IRAS 20496+4354. The PTF R-band light curve reveals that PTF10nvg brightened by more than 5 mag during the current outburst…
EIT wave observations and modeling in the STEREO era
Zhukov, Andrei N.
"EIT waves" are large-scale bright fronts observed propagating in the solar corona in association with coronal mass ejections (CMEs). An overview of the observed properties of large-scale wave-like fronts in the solar atmosphere (Moreton waves, EIT waves and similar phenomena observed in other wavelengths) is presented. The models proposed to expl…
A strong and broad Fe line in the XMM-Newton spectrum of the new X-ray transient and black hole candidate XTE J1652-453
Done, Chris; Hiemstra, Beike; Méndez, Mariano +3 more
We observed the new X-ray transient and black hole candidate XTE J1652-453 simultaneously with XMM-Newton and the Rossi X-ray Timing Explorer (RXTE). The observation was done during the decay of the 2009 outburst, when XTE J1652-453 was in the hard-intermediate state. The spectrum shows a strong and broad Fe emission line with an equivalent width …
Resolved photometry of extragalactic young massive star clusters
Bastian, N.; Larsen, S. S.; Smith, L. J. +6 more
Aims: We present colour-magnitude diagrams (CMDs) of young massive star clusters in several galaxies located well beyond the Local Group. The richness of these clusters allows us to obtain large samples of post-main sequence stars and test how well the observed CMDs are reproduced by canonical stellar isochrones.
Methods: We use imaging …
The XMM-LSS survey: optical assessment and properties of different X-ray selected cluster classes
Maccagni, D.; Chiappetti, L.; Altieri, B. +29 more
Context. XMM and Chandra opened a new area for the study of clusters of galaxies not only for cluster physics, but also for the detection of faint and distant clusters that were inaccessible with previous missions.
Aims: This article presents 66 spectroscopically confirmed clusters (0.05 ≤ z ≤ 1.5) within an area of 6 deg2 enclosed…
Spatially Resolved Nonthermal Line Broadening during the Impulsive Phase of a Solar Flare
Milligan, Ryan O.
This paper presents a detailed study of excess line broadening in extreme ultraviolet (EUV) emission lines during the impulsive phase of a C-class solar flare. In this work, which utilizes data from the EUV Imaging Spectrometer on board Hinode, the broadened line profiles were observed to be cospatial with the two hard X-ray footpoints as observed…
Origins of plasma sheet By
Petrukovich, A. A.
With 11 years of Geotail measurements we analyzed sources of plasma sheet By and constructed a model, depending on IMF By, coordinates X, Y, and geodipole tilt angle. By dependence on dipole tilt due to the neutral sheet warping and hinging has an odd (antisymmetric) profile with respect to Y. In addition, a new, e…
Can the Soft X-Ray Opacity Toward High-redshift Sources Probe the Missing Baryons?
Laor, Ari; Behar, Ehud; Dar, Arnon +1 more
Observations with the Swift satellite of X-ray afterglows of more than a hundred gamma-ray bursts (GRBs) with known redshift reveal ubiquitous soft X-ray absorption. The directly measured optical depth τ at a given observed energy is found to be constant on average at redshift z > 2, i.e., langτ(0.5 keV)rang z > 2 = 0.40 ± 0.02. S…
Dark aeolian sediments in Martian craters: Composition and sources
Poulet, F.; Jaumann, R.; Tirsch, D. +1 more
Our research focuses on the mineralogical characteristics of dark sediment deposits in Martian craters (dunes, dune fields, and sand sheets) and their local sediment sources, carried out on the basis of 70 selected localities. Morphological analyses reveal dark layers exposed in a number of crater walls, showing indications of material transport f…