Search Publications
Chandra Observations of the Field Containing HESS J1616-508
Pavlov, George G.; Kargaltsev, Oleg; Hare, Jeremy +2 more
We report the results of three Chandra observations covering most of the extent of the TeV γ-ray source HESS J1616-508 and a search for a lower-energy counterpart to this source. We detect 56 X-ray sources, 37 of which have counterparts at lower frequencies, including a young massive star cluster, but none of them appear to be a particularly promi…
First detection of a THz water maser in NGC 7538-IRS1 with SOFIA and new 22 GHz e-MERLIN maps
Menten, K. M.; Schneider, N.; Bontemps, S. +7 more
Context. The formation of massive stars (M> 10M⊙, L > 103L⊙) is still not well understood. Accumulating a large amount of mass infalling within a single entity in spite of radiation pressure is possible if, in addition to several other conditions, enough thermal energy is released. Despite numerous water line…
Search for Exoplanets around Northern Circumpolar Stars. II. The Detection of Radial Velocity Variations in M Giant Stars HD 36384, HD 52030, and HD 208742
Lee, Byeong-Cheol; Park, Myeong-Gu; Han, Inwoo +8 more
We present the detection of long-period RV variations in HD 36384, HD 52030, and HD 208742 by using the high-resolution, fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) for the precise radial velocity (RV) survey of about 200 northern circumpolar stars. Analyses of RV data, chromospheric activity indicators, and bisector variations spa…
FUSE Spectroscopy of the Accreting Hot Components in Symbiotic Variables
Sion, Edward M.; Godon, Patrick; Mikolajewska, Joanna +2 more
We have conducted a spectroscopic analysis of the far-ultraviolet archival spectra of four symbiotic variables, EG And, AE Ara, CQ Dra, and RW Hya. RW Hya and EG And have never had a recorded outburst, while CQ Dra and AE Ara have outburst histories. We analyze these systems while they are in quiescence in order to help reveal the physical propert…
Ages and structural and dynamical parameters of two globular clusters in the M81 group
Zou, Hu; Nie, Jundan; Yuan, Qirong +10 more
GC-1 and GC-2 are two globular clusters (GCs) in the remote halo of M81 and M82 in the M81 group discovered by Jang et al. using the Hubble Space Telescope (HST) images. These two GCs were observed as part of the Beijing-Arizona-Taiwan-Connecticut (BATC) Multicolor Sky Survey using 14 intermediate-band filters covering a wavelength range of 4000-1…
Pinnacles on the 67P comet nucleus: Evidence for large scale erosion and hierarchical agglomeration of the nucleus
Keller, H. U.; Mall, U.; Basilevsky, A. T. +3 more
GAIA Parallax Zero Point from RR Lyrae Stars
Kollmeier, Juna A.; Gould, Andrew
Like Hipparcos, Gaia is designed to give absolute parallaxes, independent of any astrophysical reference system. And indeed, Gaia's internal zero-point error for parallaxes is likely to be smaller than any individual parallax error. Nevertheless, due in part to mechanical issues of unknown origin, there are many astrophysical questions for which t…
XMM-Newton view of X-ray overdensities from nearby galaxy clusters: the environmental dependencies
Hudaverdi, Murat; Caglar, Turgay
In this work, we studied 10 nearby (z ≤ 0.038) galaxy clusters to understand possible interactions between hot plasma and member galaxies. A multi-band source detection was applied to detect point-like structures within the intra-cluster medium. We examined the spectral properties of a total of 391 X-ray point sources within each cluster's potenti…
Analysis of the Amplitude of the Sunyaev-Zel’dovich Effect out to Redshift z = 0.8
López-Corredoira, M.; Génova-Santos, R. T.; Gutiérrez, C. M.
The interaction of the cosmic microwave background (CMB) with the hot gas in clusters of galaxies, the so-called Sunyaev-Zel’dovich (SZ) effect, is a very useful tool that allows us to determine the physical conditions in such clusters and fundamental parameters of the cosmological models. In this work, we determine the dependence of the SZ surfac…
Are All Flare Ribbons Simply Connected to the Corona?
Judge, Philip G.; Paraschiv, Alin; Lacatus, Daniela +2 more
We consider the observational basis for the belief that flare ribbons in the chromosphere result from energy transport from the overlying corona. We study ribbons of small flares using magnetic and intensity data from the Hinode, Solar Dynamics Observatory, and IRIS missions. While most ribbons appear connected to the corona and overlie regions of…