Search Publications
A Three-dimensional View of the Remnant of Nova Persei 1901 (GK Per)
Corradi, R. L. M.; Santander-García, M.; Rodríguez-Gil, P. +4 more
We present a kinematical study of the optical ejecta of GK Per. It is based on proper-motion measurements of 282 knots from ~20 images spanning 25 years. Doppler shifts are also computed for 217 knots. The combination of proper motions and radial velocities allows a unique three-dimensional view of the ejecta to be obtained. The main results are a…
DRAFTS: A Deep, Rapid Archival Flare Transient Search in the Galactic Bulge
Hawley, Suzanne L.; Osten, Rachel A.; Sahu, Kailash +1 more
We utilize the Sagittarius Window Eclipsing Extrasolar Planet Search Hubble Space Telescope/Advanced Camera for Surveys data set for a Deep Rapid Archival Flare Transient Search to constrain the flare rate toward the older stellar population in the Galactic bulge. During seven days of monitoring 229,293 stars brighter than V = 29.5, we find eviden…
Double Horizontal Branches in NGC 6440 and NGC 6569 Unveiled by the VVV Survey
Minniti, Dante; Geisler, Doug; Moni Bidin, Christian +5 more
We report the discovery of a peculiar horizontal branch (HB) in NGC 6440 and NGC 6569, two massive and metal-rich Galactic globular clusters (GGCs) located in the Galactic bulge, within 4 kpc from the Galactic center. In both clusters, two distinct clumps are detected at the level of the cluster HB, separated by only ~0.1 mag in the K s…
Thermal to Nonthermal Energy Partition at the Early Rise Phase of Solar Flares
Fleishman, Gregory D.; Altyntsev, Alexander A.; Lesovoi, Sergey V. +1 more
In some flares, the thermal component appears much earlier than the nonthermal component in the X-ray range. Using sensitive microwave observations, we revisit this finding made by Battaglia et al. based on a thorough analysis of RHESSI data. We have found that nonthermal microwave emission produced by accelerated electrons with energy of at least…
The Central Engine Structure of 3C120: Evidence for a Retrograde Black Hole or a Refilling Accretion Disk
Reynolds, Christopher S.; Cowperthwaite, Philip S.
The broad-line radio galaxy 3C120 is a powerful source of both X-ray and radio emission including superluminal jet outflows. We report on our reanalysis of 160 ks of Suzaku data taken in 2006, previously examined by Kataoka et al. Spectral fits to the X-ray Imaging Spectrometer and Hard X-ray Detector/positive intrinsic negative data over a range …
Testing Nonstandard Cosmological Models with SNLS3 Supernova Data and Other Cosmological Probes
Li, Zhengxiang; Wu, Puxun; Yu, Hongwei
We investigate the implications for some nonstandard cosmological models using data from the first three years of the Supernova Legacy Survey (SNLS3), assuming a spatially flat universe. A comparison between the constraints from the SNLS3 and those from other SN Ia samples, such as the ESSENCE, Union2, SDSS-II, and Constitution samples, is given a…
A New Method to Constrain Supernova Fractions Using X-Ray Observations of Clusters of Galaxies
Bulbul, Esra; Loewenstein, Michael; Smith, Randall K.
Supernova (SN) explosions enrich the intracluster medium (ICM) both by creating and dispersing metals. We introduce a method to measure the number of SNe and relative contribution of Type Ia supernovae (SNe Ia) and core-collapse supernovae (SNe cc) by directly fitting X-ray spectral observations. The method has been implemented as an XSPEC model c…
The Clustered Nature of Star Formation. Pre-main-sequence Clusters in the Star-forming Region NGC 602/N90 in the Small Magellanic Cloud
Gouliermis, Dimitrios A.; Gennaro, Mario; Dolphin, Andrew E. +3 more
Located at the tip of the wing of the Small Magellanic Cloud (SMC), the star-forming region NGC 602/N90 is characterized by the H II nebular ring N90 and the young cluster of pre-main-sequence (PMS) and early-type main-sequence stars NGC 602, located in the central area of the ring. We present a thorough cluster analysis of the stellar sample iden…
Post-Coronal Mass Ejection Plasma Observed by Hinode
Raymond, J. C.; Landi, E.; Hara, H. +1 more
In the present work we study the evolution of an active region after the eruption of a coronal mass ejection (CME) using observations from the EIS and XRT instruments on board Hinode. The field of view includes a post-eruption arcade, a current sheet, and a coronal dimming. The goal of this paper is to provide a comprehensive set of measurements f…
Localizing INTEGRAL Sources with Chandra: X-Ray and Multi-wavelength Identifications and Energy Spectra
Rahoui, Farid; Kalemci, Emrah; Bodaghee, Arash +5 more
We report on Chandra observations of 18 hard X-ray (>20 keV) sources discovered with the INTEGRAL satellite near the Galactic plane. For 14 of the INTEGRAL sources, we have uncovered one or two potential Chandra counterparts per source. These provide soft X-ray (0.3-10 keV) spectra and subarcsecond localizations, which we use to identify counte…