Search Publications
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…
Searching for X-ray emission from AGB stars
Montez, R.; Kastner, J.; Ramstedt, S. +1 more
Context. Magnetic fields have been measured around asymptotic giant branch (AGB) stars of all chemical types using maser polarization observations. If present, a large-scale magnetic field would lead to X-ray emission, which should be observable using current X-ray observatories.
Aims: The aim is to search the archival data for AGB stars that…
X-ray colour-colour selection for heavily absorbed active galactic nuclei
Nandra, Kirpal; Brightman, Murray
We present a method for the identification of heavily absorbed active galactic nuclei (AGN) (NH > 1023 cm-2) from X-ray photometric data. We do this using a set of XMM-Newton reference spectra of local galaxies for which we have accurate NH information, as described in Brightman & Nandra. The tech…
Self-similarity of temperature profiles in distant galaxy clusters: the quest for a universal law
Molendi, S.; Gastaldello, F.; Ettori, S. +1 more
Context. We present the XMM-Newton temperature profiles of 12 bright (LX > 4 × 1044 erg s-1) clusters of galaxies at 0.4 < z < 0.9, having an average temperature in the range 5 ≲ kT ≲ 11 keV.
Aims: The main goal of this paper is to study for the first time the temperature profiles of a sample of high-…
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…
X-Raying the Beating Heart of a Newborn Star: Rotational Modulation of High-energy Radiation from V1647 Ori
Hamaguchi, Kenji; Petre, Robert; Kastner, Joel H. +5 more
We report a periodicity of ~1 day in the highly elevated X-ray emission from the protostar V1647 Ori during its two recent multiple-year outbursts of mass accretion. This periodicity is indicative of protostellar rotation at near-break-up speed. Modeling of the phased X-ray light curve indicates that the high-temperature (~50 MK), X-ray-emitting p…
Toward Identifying the Unassociated Gamma-Ray Source 1FGL J1311.7-3429 with X-Ray and Optical Observations
Cheung, C. C.; Kataoka, J.; Kawai, N. +9 more
We present deep optical and X-ray follow-up observations of the bright unassociated Fermi-LAT gamma-ray source 1FGL J1311.7-3429. The source was already known as an unidentified EGRET source (3EG J1314-3431, EGR J1314-3417), hence its nature has remained uncertain for the past two decades. For the putative counterpart, we detected a quasi-sinusoid…
Discovery of a Significant Magnetic Cataclysmic Variable Population in the Limiting Window
van den Berg, Maureen; Grindlay, Jonathan E.; Servillat, Mathieu +2 more
We have discovered 10 periodic X-ray sources from the 1 Ms Chandra ACIS observation of the Limiting Window (LW), a low-extinction region (AV ~ 3.9) at 1fdg4 south of the Galactic center. The observed periods (~1.3-3.4 hr) and the X-ray luminosities (1031.8-32.9 erg s-1 at 8 kpc) of the 10 periodic sources, combined…