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Double-lined spectroscopic binaries in M11
Kovalev, Mikhail; Straumit, Ilya
We have developed a new method for spectral analysis of binaries. Our method successfully identifies double-lined spectroscopic binary (SB2) candidates from high-resolution Gaia-ESO spectra. Compared to the commonly used cross-correlation function analysis, it works for binaries with rapidly rotating components. We test our method on synthetic and…
Galactic H II region IRAS 17149 - 3916 - a multiwavelength study
Tej, Anandmayee; Das, Swagat R.; Vig, Sarita +3 more
This paper presents a multiwavelength investigation of the Galactic H II region IRAS 17149 - 3916. Using the Giant Meterwave Radio Telescope, India, first low-frequency radio continuum observations at 610 and 1280 MHz for this region are presented. The ionized gas emission displays an interesting cometary morphology, which is likely powered by the…
Semi-supervised classification and clustering analysis for variable stars
Catelan, M.; Protopapas, P.; Pichara, K. +1 more
The immense amount of time series data produced by astronomical surveys has called for the use of machine learning algorithms to discover and classify several million celestial sources. In the case of variable stars, supervised learning approaches have become commonplace. However, this needs a considerable collection of expert-labelled light curve…
Path-lengths in the quiet Sun transition region using O IV lines from IRIS
Del Zanna, Giulio; Rao, Yamini K.; Mason, Helen E. +1 more
We use spectroscopic diagnostics to determine different plasma parameters in the transition region of the quiet Sun. The electron number density from O IV lines using high-resolution spectral observations from the Interface Region Imaging Spectrograph (IRIS) are estimated to be around 1010 cm-3, in agreement with literature v…
Broad-band spectral analysis of Mrk 926 using multi-epoch X-ray observations
Buisson, D. J. K.; Russell, T. D.; Lohfink, A. M. +3 more
The X-ray spectra of some active galactic nuclei (AGNs) show a soft X-ray excess, emission in excess to the extrapolated primary X-ray continuum below 2 keV. Recent studies have shown that this soft excess can be described well as originating from either a relativistic ionized reflection, the extreme blurring of the reprocessed emission from the i…
Discovery of non-equilibrium ionization plasma associated with the North Polar Spur and Loop I
Kataoka, Jun; Sofue, Yoshiaki; Yamamoto, Marino
We investigated the detailed plasma condition of the North Polar Spur (NPS)/Loop I using archival Suzaku data. In previous research, collisional ionization equilibrium (CIE) have been assumed for X-ray plasma state, but we also assume non-equilibrium ionization (NEI) to check the plasma condition in more detail. We found that most of the plasma in…
A WHIM origin for the soft excess emission in the Coma cluster
Bonamente, Massimiliano; Lieu, Richard; Mirakhor, Mohammad +1 more
This paper provides a new analysis of ROSAT observations of the Coma cluster, to determine the amount of soft X-ray radiation in excess of the contribution from the hot intracluster medium (ICM). The re-analysis is made possible by a high-resolution study of the hot ICM with the XMM-Newton and Planck telescopes out to the cluster's virial radius. …
Broad-line region clouds orbiting an AGN sample
Logan, C. H. A.; Llerena, M.; Armijos-Abendaño, J. +1 more
We present a spectral and temporal analysis of XMM-Newton data from a sample of six galaxies (NGC 3783, Mrk 279, Mrk 766, NGC 3227, NGC 7314, and NGC 3516). Using the hardness-ratio curves, we identify time intervals in which clouds are eclipsing the central X-ray source in five of the six sources. We detect three occultations in NGC 3227 and one …
H α-based star formation rates in and around z 0.5 EDisCS clusters
Weiner, Benjamin J.; Teplitz, Harry I.; Moustakas, John +14 more
We investigate the role of environment on star formation rates (SFRs) of galaxies at various cosmic densities in well-studied clusters. We present the star-forming main sequence for 163 galaxies in four EDisCS clusters in the range 0.4 < z < 0.7. We use Hubble Space Telescope/Wide Field Camera 3 observations of the H α emission line to span …
Weather forecast of the Milky Way: shear and stellar feedback determine the lives of Galactic-scale filaments
Li, Guang-Xing; Chen, Bing-Qiu; Zhou, Ji-Xuan
The interstellar medium (ISM) is an inseparable part of the Milky Way ecosystem whose evolutionary history remains a challenging question. We trace the evolution of the molecular ISM using a sample of young stellar objects (YSO) association-molecular cloud complex (YSO-MC complex). We derive their three-dimensional (3D) velocities by combining the…