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IMF, SFR and stellar depletion in the local Galactic plane, based on improved Hipparcos samples of single stars
Schröder, K. -P.; Dawson, S. A.
We have used the recently reduced Hipparcos data and the Washington Double Star catalogue to derive two volume- and magnitude-limited samples of single stars in the Galactic plane. The star count method has been used to compare synthetic to empirical samples of stars within both the main sequence and the evolved regions of the Hertzsprung-Russell …
Ultraviolet study of the active interacting binary star R Arae using archival IUE data
Sahade, Jorge; Guinan, Edward F.; Reed, Phillip A. +7 more
The eclipsing and strongly interacting binary star system R Arae (HD 149730) is in a very active and very short-lived stage of its evolution. R Ara consists of a B9V primary and an unknown secondary. We have collected the International Ultraviolet Explorer (IUE) archival data on R Ara, with most of the data being studied for the first time. There …
X-ray emission characteristics of two Wolf-Rayet binaries: V444 Cyg and CD Cru
Pandey, J. C.; Singh, K. P.; Kumar, Brijesh +2 more
Using data from observations made with XMM-Newton, we present an X-ray analysis of two Wolf-Rayet (WR) binaries: V444 Cyg and CD Cru. The X-ray light curves show the phase-locked variability in both binaries, where the flux increased by a factor of ~2 for V444 Cyg and ~1.5 for CD Cru, from minimum to maximum. The maximum luminosities in the 0.3-7.…
A joint Chandra and XMM-Newton view of Abell 3158: a massive off-centre cool gas clump as a robust diagnostic of a merger stage
Xu, Haiguang; Zhang, Zhongli; Gu, Liyi +5 more
In previous works, the nearby galaxy cluster Abell 3158 was reported to possess a relatively regular, relaxed morphology in the X-ray band. By analysing the Chandra and XMM-Newton archived data of Abell 3158, we have identified a bow-edge-shaped discontinuity in the X-ray surface brightness distribution about 120h-171 kpc wes…
A far-ultraviolet variability survey of the globular cluster M80
Knigge, C.; Long, K. S.; Zurek, D. R. +2 more
We have searched for variable sources in the core region of M80, using far-ultraviolet (FUV) data taken with the Advanced Camera for Surveys on board the Hubble Space Telescope. We found three sources that exhibit strong signs of variability in our data. Among these is source TDK1, which we believe to be an RRLyrae star that reached maximum bright…
Cepheid period-luminosity relation from the AKARI observations
Onaka, Takashi; Ita, Yoshifusa; Ngeow, Chow-Choong +3 more
In this paper, we derive the period-luminosity (P-L) relation for Large Magellanic Cloud (LMC) Cepheids based on mid-infrared AKARI observations. AKARI's Infrared Camera sources were matched to the Optical Gravitational Lensing Experiment-III (OGLE-III) LMC Cepheid catalogue. Together with the available I-band light curves from the OGLE-III catalo…
Infrared identification of 4U1323-619 revisited
Zolotukhin, Ivan Yu.; Revnivtsev, Mikhail G.; Shakura, Nikolai I.
We re-examine the infrared counterpart of the dipping low-mass X-ray binary 4U1323-619. New X-ray data available from the XMM and Chandra observatories combined with archival infrared observations from the European Southern Observatory 3.6-m New Technology Telescope allow us to define a new possible counterpart. We present here its photometric pro…
Unresolved X-ray emission in M31 and constraints on progenitors of classical novae
Bogdán, Á.; Gilfanov, M.
We investigate unresolved X-ray emission from M31 based on an extensive set of archival XMM-Newton and Chandra data. We show that extended emission, found previously in the bulge and thought to be associated with a large number of faint compact sources, extends to the disc of the galaxy with similar X-ray to K-band luminosity ratio. We also detect…
A multiwavelength view of the protostellar binary IRAS 04325+2402: a case for turbulent fragmentation
Scholz, A.; Saviane, I.; Jayawardhana, R. +6 more
IRAS 04325+2402 (hereinafter IRAS 04325) is a complex protostellar system hosting two young stellar objects (AB and C) at a separation of 1250 au. Here, we present a new deep Gemini imaging and spectroscopy for the system covering the wavelength regime from 1 to 12 µm as well as Submillimeter Array interferometry at 870 µm, in combinat…
The Algol binary system KZ Pavonis revisited
Erdem, A.; Budding, E.; Sürgit, D.
We present results from analysing new spectroscopic and photometric observations of the KZ Pav (IDS 20490-7048 A-BC) multiple system. High-resolution spectra were taken at the Mt John University Observatory in 2007 and 2008. Radial velocities for the close binary were determined from cross-correlation and spectral disentangling methods. The result…