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Chandra Detection of Intracluster X-Ray sources in Virgo
Liu, Chengze; Peng, Eric W.; Li, Zhiyuan +1 more
We present a survey of X-ray point sources in the nearest and dynamically young galaxy cluster, Virgo, using archival Chandra observations that sample the vicinity of 80 early-type member galaxies. The X-ray source populations at the outskirts of these galaxies are of particular interest. We detect a total of 1046 point sources (excluding galactic…
ALMA Observations of SMM11 Reveal an Extremely Young Protostar in Serpens Main Cluster
Ohashi, Nagayoshi; Tomisaka, Kohji; Yen, Hsi-Wei +8 more
We report the discovery of an extremely young protostar, SMM11, located in the associated submillimeter condensation in the Serpens Main cluster using the Atacama Large Millimeter/submillimeter Array (ALMA) during its Cycle 3 at 1.3 mm and an angular resolution of ∼ 0\buildrel{\prime\prime}\over{.} 5∼ 210 {AU}. SMM11 is a Class 0 protostar without…
Probing Subsurface Flows in NOAA Active Region 12192: Comparison with NOAA 10486
Hill, F.; Tripathy, S. C.; Jain, Kiran
NOAA Active Region (AR) 12192 is the biggest AR observed in solar cycle 24 so far. This was a long-lived AR that survived for four Carrington rotations (CRs) and exhibited several unusual phenomena. We measure the horizontal subsurface flows in this AR in multiple rotations using the ring-diagram technique of local helioseismology and the Global O…
A Spitzer Spectral Atlas of Low-mass Active Galactic Nuclei
Ho, Luis C.; Barth, Aaron J.; Greene, Jenny E. +1 more
We present Spitzer low-resolution Infrared Spectrograph (IRS) spectra (5 µm ≲ λ ≲ 40 µm) of a sample of 41 Type 1 and Type 2 active galactic nuclei (AGNs) with estimated black hole masses of {M}{BH} ≲ {10}6 {M}⊙ , in order to probe the validity of unification models in this mass regime. We find that the…
Mid-infrared interferometric variability of DG Tauri : Implications for the inner-disk structure
Jaffe, W.; Ábrahám, P.; Chen, L. +12 more
Context. DG Tau is a low-mass pre-main sequence star, whose strongly accreting protoplanetary disk exhibits a so-far enigmatic behavior: its mid-infrared thermal emission is strongly time-variable, even turning the 10 µm silicate feature from emission to absorption temporarily.
Aims: We look for the reason for the spectral variability a…
The XXL survey: First results and future
Smith, G. P.; Okabe, N.; Chiappetti, L. +108 more
The XXL survey currently covers two 25 deg2 patches with XMM observations of ∼10 ks. We summarize the scientific results associated with the first release of the XXL dataset, which occurred in mid-2016. We review several arguments for increasing the survey depth to 40 ks during the next decade of XMM operations. X-ray (z < 2) cluster…
Testing the Universality of the Stellar IMF with Chandra and HST
Lehmer, B. D.; Hornschemeier, A. E.; Maccarone, T. +8 more
The stellar initial mass function (IMF), which is often assumed to be universal across unresolved stellar populations, has recently been suggested to be “bottom-heavy” for massive ellipticals. In these galaxies, the prevalence of gravity-sensitive absorption lines (e.g., Na I and Ca II) in their near-IR spectra implies an excess of low-mass (m≲ 0.…
The intricate Galaxy disk: velocity asymmetries in Gaia-TGAS
Prusti, T.; Figueras, F.; Antoja, T. +3 more
We use Gaia-TGAS data to compare the transverse velocities in Galactic longitude (coming from proper motions and parallaxes) in the Milky Way disk for negative and positive longitudes as a function of distance. The transverse velocities are strongly asymmetric and deviate significantly from the expectations for an axisymmetric galaxy. The value an…
A systematic analysis of the XMM-Newton background: III. Impact of the magnetospheric environment
Tiengo, Andrea; De Luca, Andrea; Marelli, Martino +6 more
A detailed characterization of the particle induced background is fundamental for many of the scientific objectives of the Athena X-ray telescope, thus an adequate knowledge of the background that will be encountered by Athena is desirable. Current X-ray telescopes have shown that the intensity of the particle induced background can be highly vari…
Radio and infrared study of the star-forming region IRAS 20286+4105
Ojha, D. K.; Vig, S.; Ghosh, S. K. +3 more
In this paper, we present a multiwavelength investigation of the star-forming complex IRAS 20286+4105, located in the Cygnus X region. Near-infrared K-band data are used to revisit the cluster/stellar group identified in previous studies. Radio continuum observations at 610 and 1280 MHz show the presence of a H II region possibly powered by a star…