Search Publications
Flight model performance test results of a helium dewar for the soft X-ray spectrometer onboard ASTRO-H
Mitsuda, Kazuhisa; Fujimoto, Ryuichi; Yoshida, Seiji +10 more
ASTRO-H is a Japanese X-ray astronomy satellite, scheduled to be launched in fiscal year 2015. The mission includes a soft X-ray spectrometer instrument (SXS), which contains an X-ray micro calorimeter operating at 50 mK by using an adiabatic demagnetization refrigerator (ADR). The heat sink of the ADR is superfluid liquid helium below 1.3 K. The …
Chandra View of Magnetically Confined Wind in HD191612: Theory Versus Observations
Zhekov, Svetozar A.; Nazé, Yaël; ud-Doula, Asif
High-resolution spectra of the magnetic star HD 191612 were acquired using the Chandra X-ray Observatory at both maximum and minimum emission phases. We confirm the flux and hardness variations previously reported with XMM-Newton, demonstrating the high repeatability of the behavior of HD 191612 over a decade. The line profiles appear typical for …
The ACS Fornax Cluster Survey. XII. Diffuse Star Clusters in Early-type Galaxies
Jordán, Andrés; Côté, Patrick; Peng, Eric W. +5 more
Diffuse star clusters (DSCs) are old and dynamically hot stellar systems that have lower surface brightness and more extended morphology than globular clusters (GCs). Using the images from Hubble Space Telescope (HST)/ACS Fornax Cluster Survey, we find that 12 out of 43 early-type galaxies (ETGs) in the Fornax Cluster host significant numbers of D…
The SXDF-ALMA 2-arcmin2 Deep Survey: Stacking Rest-frame Near-infrared Selected Objects
Tamura, Yoichi; Kohno, Kotaro; Caputi, Karina I. +24 more
We present stacking analyses on our ALMA deep 1.1 mm imaging in the Subaru/XMM-Newton Deep Survey Field using 1.6 and 3.6 µm selected galaxies in the CANDELS WFC3 catalog. We detect a stacked flux of ∼0.03-0.05 mJy, corresponding to {L}{IR}\lt {10}11 {L}⊙ and a star formation rate (SFR) of ∼ 15 {M}⊙
Period-Luminosity relations derived from the OGLE-III first-overtone mode Cepheids in the Magellanic Clouds
Ngeow, Chow-Choong; Kanbur, Shashi M.; Bhardwaj, Anupam +1 more
We present multiband Period-Luminosity (PL) relations for first-overtone mode Cepheids in the Small Magellanic Cloud (SMC). We derive optical band PL relations and the Wesenheit function using VI mean magnitudes from the Optical Gravitational Lensing Experiment (OGLE-III) survey. We cross-match OGLE-III first-overtone mode Cepheids to the 2MASS an…
The SLUGGS survey: chromodynamical modelling of the lenticular galaxy NGC 1023
Cortesi, Arianna; Chies-Santos, Ana L.; Forbes, Duncan A. +12 more
Globular clusters (GCs) can be considered discrete, long-lived, dynamical tracers that retain crucial information about the assembly history of their parent galaxy. In this paper, we present a new catalogue of GC velocities and colours for the lenticular galaxy NGC 1023, we study their kinematics and spatial distribution, in comparison with the un…
Chemical evolution of the HC3N and N2H+ molecules in dense cores of the Vela C giant molecular cloud complex
Sanhueza, Patricio; Choi, Minho; Tatematsu, Ken'ichi +5 more
We have observed the HC3N(J = 10-9) and N2H+ (J = 1-0) lines toward the Vela C molecular clouds with the Mopra 22 m telescope to study the chemical characteristics of dense cores. The intensity distributions of these molecules are similar to each other at an angular resolution of 53″, corresponding to 0.19 pc, sugg…
Distribution of hydrogen and oxygen ion species in the plasmasheet
Wang, Jing; Cao, Jinbin; Liu, Wenlong
In this paper, using data obtained by Cluster 4 satellite from 2001 to 2012, we statistically investigate the spatial distributions of H+ and O+ in the magnetotail plasmasheet and their relation with geomagnetic indices. Our work outlines the existence of two regions with enhanced O+ concentration in the tail plasm…
Young Stellar Populations in MYStIX Star-forming Regions: Candidate Protostars
Feigelson, Eric D.; Povich, Matthew S.; Getman, Konstantin V. +2 more
The Massive Young Star-Forming Complex in Infrared and X-ray (MYStIX) project provides a new census on stellar members of massive star-forming regions within 4 kpc. Here the MYStIX Infrared Excess catalog and Chandra-based X-ray photometric catalogs are mined to obtain high-quality samples of Class I protostars using criteria designed to reduce ex…
Broad-band X-ray emission and the reality of the broad iron line from the neutron star-white dwarf X-ray binary 4U 1820-30
Misra, R.; Dewangan, G. C.; Mondal, Aditya S. +3 more
Broad relativistic iron lines from neutron star X-ray binaries are important probes of the inner accretion disc. The X-ray reflection features can be weakened due to strong magnetic fields or very low iron abundances such as is possible in X-ray binaries with low mass, first generation stars as companions. Here, we investigate the reality of the b…