Search Publications
Interpretation of a Variable Reflection Nebula Associated with HBC 340 and HBC 341 in NGC 1333
Hillenbrand, L. A.; Dahm, S. E.
We present multi-epoch, R-band imaging obtained from the Palomar Transient Factory of a small, fan-shaped reflection nebula in NGC 1333 that experiences prominent brightness fluctuations. Photometry of HBC 340 (K7e) and HBC 341 (M5e), a visual pair of late-type, young stellar objects lying near the apex of the nebula, demonstrates that while both …
The Radial Distribution of Mono-metallicity Populations in the Galactic Disk as Evidence for Two-phase Disk Formation
Domínguez-Tenreiro, R.; Obreja, A.; Brook, C. B. +2 more
Recent determinations of the radial distributions of mono-metallicity populations (MMPs, I.e., stars in narrow bins in [Fe/H] within wider [α/Fe] ranges) by the SDSS-III/APOGEE DR12 survey cast doubts on the classical thin- and thick-disk dichotomy. The analysis of these observations led to the non-[α /Fe] enhanced populations splitting into MMPs …
The supersoft X-ray source in V5116 Sagittarii . I. The high resolution spectra
Greiner, J.; Hernanz, M.; Sala, G. +1 more
Context. Classical nova explosions occur on the surface of an accreting white dwarf in a binary system. After ejection of a fraction of the envelope and when the expanding shell becomes optically thin to X-rays, a bright source of supersoft X-rays arises, powered by residual H burning on the surface of the white dwarf. While the general picture of…
Thermal Modeling of Comet-like Objects from AKARI Observation
Usui, Fumihiko; Ishiguro, Masateru; Bach, Yoonsoo P.
We investigated the physical properties of the comet-like objects 107P/(4015) Wilson-Harrington (4015WH) and P/2006 HR30 (Siding Spring; HR30) by applying a simple thermophysical model to the near-infrared spectroscopy and broadband observation data obtained by the AKARIsatellite of JAXA when they showed no detectable comet-like activity. We selec…
The hierarchical triple system DY Lyncis
Lehmann, H.; Kamiński, K.; Dimitrov, W. +3 more
We present the results of a six-year spectroscopic monitoring of DY Lyncis. Three different echelle spectrographs were used to collect the spectroscopic data. Each DY Lyncis spectrum contains lines of three different stars. Two of them belong to a very close eclipsing binary (EB) with an orbital period of 1.3 d. The reflex motion due to the third …
Oscillations in the 45 - 5000 MHz Radio Spectrum of the 18 April 2014 Flare
Monstein, Christian; Rybák, Ján; Karlický, Marian
Using a new type of oscillation map, made from the radio spectra by the wavelet technique, we study the 18 April 2014 M7.3 flare (SOL2014-04-18T13:03:00L245C017). We find a quasi-periodic character of this flare with periods in the range 65 - 115 seconds. At the very beginning of this flare, in connection with the drifting pulsation structure (pla…
Constraining the Dust Opacity Law in Three Small and Isolated Molecular Clouds
Di Francesco, J.; Sadavoy, S.; Kainulainen, J. +6 more
Density profiles of isolated cores derived from thermal dust continuum emission rely on models of dust properties, such as mass opacity, that are poorly constrained. With complementary measures from near-infrared extinction maps, we can assess the reliability of commonly used dust models. In this work, we compare Herschel-derived maps of the optic…
Emission-line stars in M31 from the SPLASH and PHAT surveys
Williams, Benjamin F.; Seth, Anil C.; Dalcanton, Julianne J. +7 more
We present a sample of 224 stars that emit Hα (Hα stars) in the Andromeda galaxy (M31). The stars were selected from ∼5000 spectra, collected as part of the Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo survey using Keck II/DEIMOS. We used six-filter Hubble Space Telescope photometry from the Panchromatic Hubble Andromeda Tre…
B stars seen at high resolution by XMM-Newton
Nazé, Yaël; Cazorla, Constantin
We report on the properties of 11 early B stars observed with gratings on board XMM-Newton and Chandra, thereby doubling the number of B stars analysed at high resolution. The spectra typically appear soft, with temperatures of 0.2-0.6 keV, and moderately bright (log [LX/LBOL] -7) with lower values for later type stars. In li…
Foreground of Gamma-Ray Bursts (grbs) from Akari Fis Data
Doi, Yasuo; Zahorecz, Sarolta; Toth, L. Viktor +4 more
A significant number of the parameters of a gamma-ray burst (GRB) and its host galaxy are calculated from the afterglow. There are various methods obtaining extinction values for the necessary correction for galactic foreground. These are: galaxy counts, from HI 21 cm surveys, from spectroscopic measurements and colors of nearby Galactic stars, or…