Search Publications
Turbulent Convection Model in the Overshooting Region. I. Effects of the Convective Mixing in the Solar Overshooting Region
Li, Y.; Zhang, Q. S.
The overshooting in the framework of the turbulent convection model is investigated in the solar overshooting region. The overshooting mixing is treated as a diffusive process. It is found that the sound speed profile can be improved to be in good agreement with helioseismic inversions. The bump in the sound speed differences between solar models …
Pervasive Linear Polarization Signals in the Quiet Sun
Bellot Rubio, L. R.; Orozco Suárez, D.
This paper investigates the distribution of linear polarization signals in the quiet-Sun internetwork using ultra-deep spectropolarimetric data. We reduce the noise of the observations as much as is feasible by adding single-slit measurements of the Zeeman-sensitive Fe I 630 nm lines taken by the Hinode spectropolarimeter. The integrated Stokes sp…
A New Sample of Candidate Intermediate-mass Black Holes Selected by X-Ray Variability
Awaki, Hisamitsu; Terashima, Yuichi; Kamizasa, Naoya
We present the results of X-ray variability and spectral analysis of a sample of 15 new candidates for active galactic nuclei with relatively low-mass black holes (BHs). They are selected from the Second XMM-Newton Serendipitous Source Catalogue based on strong variability quantified by normalized excess variances. Their BH masses are estimated to…
The ACS LCID Project. VII. The Blue Stragglers Population in the Isolated dSph Galaxies Cetus and Tucana
Hidalgo, S. L.; Mayer, L.; Stetson, P. B. +8 more
We present the first investigation of the Blue Straggler star (BSS) population in two isolated dwarf spheroidal galaxies of the Local Group, Cetus and Tucana. Deep Hubble Space Telescope/Advanced Camera for Surveys photometry allowed us to identify samples of 940 and 1214 candidates, respectively. The analysis of the star formation histories of th…
Discovery of Two Supernovae in the Nuclear Regions of the Luminous Infrared Galaxy IC 883
Colina, L.; Kankare, E.; Efstathiou, A. +10 more
We report the discovery of two consecutive supernovae (SNe), 2010cu and 2011hi, located at 0farcs37 (180 pc) and 0farcs79 (380 pc) projected distance, respectively, from the center of the K-band nucleus of the luminous infrared galaxy (LIRG) IC 883. The SNe were discovered in an ongoing near-infrared K-band search for core-collapse SNe in such gal…
The Unimodal Distribution of Blue Straggler Stars in M75 (NGC 6864)
Dalessandro, E.; Contreras Ramos, R.; Ferraro, F. R. +2 more
We have used a combination of multiband high-resolution and wide-field ground-based observations to image the Galactic globular cluster M75 (NGC 6864). The extensive photometric sample covers the entire cluster extension, from the very central regions out to the tidal radius, allowing us to determine the center of gravity and to construct the most…
Herschel Search for O2 toward the Orion Bar
Li, Di; van Dishoeck, Ewine F.; Encrenaz, Pierre +15 more
We report the results of a search for molecular oxygen (O2) toward the Orion Bar, a prominent photodissociation region at the southern edge of the H II region created by the luminous Trapezium stars. We observed the spectral region around the frequency of the O2 NJ = 33-12 transition at 487 GH…
XMM-Newton View of Swift J1834.9-0846 and Its Magnetar Wind Nebula
Kouveliotou, C.; Pavlov, G. G.; Göǧüş, E. +3 more
We report on the analysis of two XMM-Newton observations of the recently discovered soft gamma repeater Swift J1834.9-0846, taken in 2005 September and one month after the source went into outburst on 2011 August 7. We performed timing and spectral analyses on the point source as well as on the extended emission. We find that the source period is …
Exploring the Diversity of Groups at 0.1 < z < 0.8 with X-Ray and Optically Selected Samples
Mulchaey, John S.; Connelly, J. L.; Balogh, Michael L. +8 more
We present the global group properties of two samples of galaxy groups containing 39 high-quality X-ray-selected systems and 38 optically (spectroscopically) selected systems in coincident spatial regions at 0.12 < z < 0.79. The total mass range of the combined sample is ~(1012-5) × 1014 M ⊙. Only nine optica…
Identification of Ambient Molecular Clouds Associated with Galactic Supernova Remnant IC 443
Yun, Min S.; Koo, Bon-Chul; Lee, Jae-Joon +3 more
The Galactic supernova remnant (SNR) IC 443 is one of the most studied core-collapse SNRs for its interaction with molecular clouds. However, the ambient molecular clouds with which IC 443 is interacting have not been thoroughly studied and remain poorly understood. Using the Five College Radio Astronomy Observatory 14 m telescope, we obtained ful…