Search Publications
Multiple populations in integrated light spectroscopy of intermediate-age clusters
Salaris, Maurizio; Kamann, Sebastian; Schiavon, Ricardo P. +9 more
The presence of star-to-star light-element abundance variations (also known as multiple populations, MPs) appears to be ubiquitous within old and massive clusters in the Milky Way and all studied nearby galaxies. Most previous studies have focused on resolved images or spectroscopy of individual stars, although there has been significant effort in…
The UBV Color Evolution of Classical Novae. III. Time-stretched Color-Magnitude Diagram of Novae in Outburst
Kato, Mariko; Hachisu, Izumi
We propose a modified color-magnitude diagram for novae in outburst, i.e., (B - V)0 versus (M V - 2.5 log f s), where f s is the time-scaling factor of a (target) nova against a comparison (template) nova, (B - V)0 is the intrinsic B - V color, and M V is the absolute V magnitud…
LMC S154: the first Magellanic symbiotic recurrent nova
Gromadzki, Mariusz; Miszalski, Brent; Iłkiewicz, Krystian +3 more
Classical nova outburst has been suggested for a number of extragalactic symbiotic stars, but in none of the systems has it been proven. In this work we study the nature of one of these systems, LMC S154. We gathered archival photometric observations in order to determine the timescales and nature of variability in this system. Additionally we car…
XMM-Newton RGS Spectroscopy of the M31 Bulge. I. Evidence for a Past AGN Half a Million Years Ago
Wang, Q. Daniel; Li, Zhiyuan; Foster, Adam R. +3 more
Existing analysis based on spectra from the Reflection Grating Spectrometer (RGS) on board XMM-Newton already shows that the G-ratio of the O VII Heα triplet in the inner bulge of M31 is too high to be consistent with a pure optically thin thermal plasma in collisional ionization equilibrium (CIE). Different processes that may affect properties of…
CALSPEC: Wide Field Camera 3 Infrared Grism Spectrophotometry
Bohlin, Ralph C.; Deustua, Susana E.
The collections of spectral energy distributions (SEDs) in the Hubble Space Telescope (HST) CALSPEC database are augmented by 19 infrared (IR) SEDs from Wide Field Camera 3 (WFC3) IR grism spectra. Together, the two IR grisms, G102 and G141, cover the 0.8-1.7 µm range with resolutions of R = 200 and 150, respectively. These new WFC3 SEDs ove…
Evolution of X-ray irradiation during the 1999-2000 outburst of the black hole binary XTE J1859 + 226
Done, Chris; Kimura, Mariko
X-ray irradiation in X-ray binaries is thought to control the behaviour at the outer disc, which is observable mainly at optical wavelengths. It is generally parametrized phenomenologically, but it can also be predicted from theoretical models of irradiated discs and their coronae/winds. We test these models using five multiwavelength Hubble Space…
SOFIA FORCAST Photometry of 12 Extended Green Objects in the Milky Way
Hunter, T. R.; Cyganowski, C. J.; Friesen, R. K. +2 more
Massive young stellar objects (MYSOs) are known to undergo an evolutionary phase in which high mass accretion rates drive strong outflows. A class of objects believed to trace this phase accurately is the Galactic Legacy Infrared Midplane Survey Extraordinaire (GLIMPSE) Extended Green Object (EGO) sample, so named for the presence of extended 4.5 …
Orbital and physical parameters of eclipsing binaries from the All-Sky Automated Survey catalogue. X. Three high-contrast systems with secondaries detected with IR spectroscopy
Tamura, M.; Kambe, E.; Niemczura, E. +14 more
Aims: We present results of the combined photometric and spectroscopic analysis of three detached eclipsing binaries, the secondary components of which are not visible or are very hard to identify in the optical spectra - ASAS J052743-0359.7, ASAS J065134-2211.5, and ASAS J073507-0905.7. The first one is the known visual binary ADS 4022, and …
A Double-modulation Effect Detected in a Double-mode High-amplitude δ Scuti Star: KIC 10284901
Esamdin, Ali; Yang, Tao-Zhi
In this paper, we present an analysis of the pulsating behavior of Kepler target KIC 10284901. The Fourier transform of the high-precision light curve reveals seven independent frequencies for its light variations. Among them, the first two frequencies are main pulsation modes: F0 = 18.994054(1) day-1 and F1 = 24.335804(4) day-1
Study of the mass-ratio distribution of spectroscopic binaries - II. The boundaries of the brown-dwarf desert as seen with the APOGEE spectroscopic binaries
Mazeh, T.; Shahaf, S.
Analysis of APOGEE DR12 stellar radial velocities by Troup et al. affirmed the existence of the well-known brown-dwarf desert (BDD). They detected a dearth of spectroscopic binaries (SB) with periods shorter than ∼10-30 d and secondaries with masses in the range of ∼0.01-0.1 M_{\odot }. We reconsider here their sample of binaries, focusing on 116 …