Search Publications
Missions
Journals
Publication Years
Infrared study of the star-forming region associated with the UC HII regions G45.07+0.13 and G45.12+0.13
Azatyan, N.; Nikoghosyan, E.; Harutyunian, H. +2 more
Ultra-compact H II (UC HII) regions are an important phase in the formation and early evolution of massive stars and a key component of the interstellar medium (ISM). The main objectives of this work are to study the young stellar population associated with the G45.07+0.13 and G45.12+0.13 UC HII regions, as well as the ISM in which they are embedd…
Broad-band spectral analysis of LMXB 2S 0921-63 with Suzaku
Jain, Chetana; Dutta, Anjan; Sharma, Prince
We present the broad-band spectral analysis of the low-mass X-ray binary 2S 0921-63 by using the Suzaku archival data covering the orbital phase between 0.31 and 1.16 during four close observations. It is the first time that a broad-band spectral analysis of 2S 0921-63 has been done up to 25 keV. The 0.5-10 keV XIS count rate varied between ~1 and…
Stellar population gradients at cosmic noon as a constraint to the evolution of passive galaxies
Andreon, S.; Ditrani, F. R.; Longhetti, M. +1 more
Context. The radial variations of the stellar populations properties within passive galaxies at high redshift contain information about their assembly mechanisms, based on which galaxy formation and evolution scenarios may be distinguished.
Aims: The aim of this work is to give constraints on massive galaxy formation scenarios through one of …
X-ray pulsar HD 49798: a contracting white dwarf with a debris disk?
Chen, Wen-Cong
HD 49798/RX J0648.0C4418 is a peculiar binary including a hot subdwarf of O spectral type and a compact companion in a 1.55 day orbit. Based on the steady spin period derivative Ṗ = (−2.17 ± 0.01) × 10−15 s s−1 , the compact object was thought to be a contracting young white dwarf (WD). However, the X-ray luminosity produced …
Solar Minimum Exospheric Neutral Density Near the Subsolar Magnetopause Estimated From the XMM Soft X-Ray Observations on 12 November 2008
Pagani, C.; Kuntz, K. D.; Koutroumpa, D. +3 more
The Earth's magnetosheath and cusps emit soft X-rays due to the charge exchange between highly charged solar wind ions and exospheric hydrogen atoms. The Lunar Environment Heliospheric X-ray Imager and Solar wind Magnetosphere Ionosphere Link Explorer missions are scheduled to image the Earth's dayside magnetosphere system in soft X-rays to invest…
Search for an Alien Message to a Nearby Star
Wright, Jason T.; Gillon, Michaël; Burdanov, Artem
If alien probes have colonized the whole galaxy, they could have formed an efficient galactic-scale communication network by establishing direct gravitationally lensed links between neighboring systems. Under this scenario, observing the positions opposite the nearest ecliptic stars represents a promising artifact SETI strategy that could make it …
Open clusters with proper motions fully separatedfrom the field stars using Gaia DR2
Tadross, A. L.; Badawy, W. A.; Hendy, Y. H. M. +3 more
The study of open star clusters makes us understand a lot about the composition and construction of the Milky Way Galaxy. Thanks to the Gaia DR2 database that helps us to get the genetic members of star clusters using their proper motions and parallaxes, estimating their physical properties in a very accurate way. This study aims to detect the rea…
On the validity of the spectroscopic age indicators [Y/Mg], [Y/Al], [Y/Si], [Y/Ca], and [Y/Ti] for giant stars
Abuchaim, Yuri; Kerber, Leandro; Katime Santrich, Orlando J. +1 more
The abundance ratios [Y/Mg], [Y/Al], [Y/Si], [Y/Ca], and [Y/Ti] have been suggested as chemical clocks for solar-metallicity dwarf stars in the field as well as for giant stars in open clusters. To verify this last hypothesis, we derive these abundances ratios of 50 giant stars belonging to seven open clusters. To calculate the abundances, we anal…
Companion mass limits for 17 binary systems obtained with binary differential imaging and MagAO/Clio
Weinberger, Alycia J.; Close, Laird M.; Males, Jared R. +4 more
Improving direct detection capability close to the star through improved star subtraction and post-processing techniques is vital for discovering new low-mass companions and characterizing known ones at longer wavelengths. We present results of 17 binary star systems observed with the Magellan adaptive optics system (MagAO) and the Clio infrared c…
The CGM-GRB Study. II. Outflow-Galaxy Connection at z 2-6
Cenko, S. Bradley; Veilleux, Sylvain; Perley, Daniel +4 more
We use a sample of 27 gamma-ray bursts (GRBs) at redshift z = 2-6 to probe the outflows in their respective host galaxies (log(M */M ⊙) ~ 9-11) and search for possible relations between the outflow properties and those of the host galaxies, such as M *, the star formation rate (SFR), and the specific SFR (sSFR). Fi…