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XMM-Newton and Chandra Observations of the Galaxy Group NGC 5044. II. Metal Abundances and Supernova Fraction

Buote, David A.; Brighenti, Fabrizio; Mathews, William G. +1 more

Using new XMM and Chandra observations, we present an analysis of the metal abundances of the hot gas within a radius of 100 kpc of the bright nearby galaxy group NGC 5044. Motivated by the inconsistent abundance and temperature determinations obtained by different observers for X-ray groups, we provide a detailed investigation of the systematic e…

The Andromeda project. I. Deep HST-WFPC2 V, I photometry of 16 fields toward the disk and the halo of the M 31 galaxy. Probing the stellar content and metallicity distribution

Cacciari, C.; Bellazzini, M.; Federici, L. +2 more

We have obtained HST-WFPC2 F555W and F814W photometry for 16 fields in the vicinity of the luminous nearby spiral galaxy M 31, sampling the stellar content of the disk and the halo at different distances from the center, from ~ 20 to ~ 150 arcmin (i.e. ~ 4.5 to 35 kpc), down to limiting V and I magnitudes of ~ 27.

The Color-Magnitude Diagrams…

A Search for Core-Collapse Supernova Progenitors in Hubble Space Telescope Images

Van Dyk, Schuyler D.; Filippenko, Alexei V.; Li, Weidong

Identifying the massive progenitor stars that give rise to core-collapse supernovae (SNe) is one of the main pursuits of supernova and stellar evolution studies. Using ground-based images of recent, nearby SNe obtained primarily with the Katzman Automatic Imaging Telescope, astrometry from the Two Micron All Sky Survey, and archival images from th…

The Chandra Deep Field North Survey. XV. Optically Bright, X-Ray-Faint Sources

Hornschemeier, A. E.; Alexander, D. M.; Bauer, F. E. +7 more

We have analyzed optically bright, X-ray-faint [OBXF; i.e., log(f_X/f_R)<~-2] sources identified in an 178.9 arcmin² area having high exposure (greater than 1500 ks) within the Chandra Deep Field North 2 Ms survey. We find 43 OBXF sources in this area, making up ~15% of the X-ray sources above a 0.5-2 keV flux of …

Physical conditions in the planetary nebula Abell 30

Barlow, M. J.; Liu, X. -W.; Wesson, R.

We have analysed optical spectra of two of the hydrogen-deficient knots (J1 and J3) in the born-again planetary nebula Abell 30, together with ultraviolet (UV) spectra of knots J3 and J4. We determine electron temperatures in the knots based on several diagnostics. The [OIII] nebular-to-auroral transition ratio yields temperatures of the order of …

The Ibis-Picsit detector onboard Integral

Di Cocco, G.; Stephen, J. B.; Gianotti, F. +6 more

PICsIT is the high-energy detector layer of the IBIS Imager, composed of 4096 CsI(Tl) scintillator detectors 8.4 x 8.4x 300 mm in size with PhotoDiode readout. The detector operates in the 175 keV-20.4 MeV range and its data generation modes make it possible to collect information from single events and multiple coincident events. PICsIT is surrou…

XMM-Newton discovery of an X-ray filament in Coma

Finoguenov, A.; Briel, U. G.; Henry, J. P.

XMM-Newton observations of the outskirts of the Coma cluster of galaxies confirm the existence of a soft X-ray excess claimed previously and show it comes from warm thermal emission. Our data provide a robust estimate of its temperature ( ~ 0.2 keV) and oxygen abundance ( ~ 0.1 solar). Using a combination of XMM-Newton and ROSAT All-Sky Survey dat…

Periodicities in solar coronal mass ejections

Wang, Shui; Fan, Zuhui; Lou, Yu-Qing +2 more

Mid-term quasi-periodicities in solar coronal mass ejections (CMEs) during the most recent solar maximum cycle 23 are reported here for the first time using the four-year data (1999 February 5 to 2003 February 10) of the Large Angle Spectrometric Coronagraph on board the Solar and Heliospheric Observatory. In parallel, mid-term quasi-periodicities…

XMM observation of M 87. II. Abundance structure of the interstellar and intergalactic medium

Finoguenov, A.; Böhringer, H.; Matsushita, K.

Based on a detailed study of the temperature structure of the intracluster medium in the halo of M 87, abundance profiles of 7 elements, O, Mg, Si, S, Ar, Ca, and Fe are derived. In addition, abundance ratios are derived from the ratios of line strengths, whose temperature dependences are small within the temperature range of the ICM of M 87. The …

The Slow Temperature Equilibration behind the Shock Front of SN 1006

Vink, Jacco; Kaastra, Jelle S.; Laming, J. Martin +2 more

We report on the observation of O VII Doppler line broadening in a compact knot at the edge of SN 1006 detected with the reflective grating spectrometer on board XMM-Newton. The observed line width of σ=3.4+/-0.5 eV at a line energy of 574 eV indicates an oxygen temperature of kT=528+/-150 keV. Combined with the observed electron temperature of ~1…