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Validations and Corrections of the SFD and Planck Reddening Maps Based on LAMOST and Gaia Data
Chen, Bingqiu; Yuan, Haibo; Sun, Yang
Precise correction of dust reddening is fundamental to obtain the intrinsic parameters of celestial objects. The Schlegel et al. (SFD) and the Planck 2D extinction maps are widely used for reddening correction. In this work, using accurate reddening determinations of about 2 million stars from the Large Sky Area Multi-Object Fiber Spectroscopic Te…
Dynamically Tagged Groups of Metal-poor Stars. II. The Radial Velocity Experiment Data Release 6
Huang, Yang; Beers, Timothy C.; Placco, Vinicius M. +2 more
Orbital characteristics based on Gaia Early Data Release 3 astrometric parameters are analyzed for ~8000 metal-poor stars ([Fe/H] ≤ -0.8) compiled from the Radial Velocity Experiment (RAVE) Data Release 6. Selected as metal-poor candidates based on broadband photometry, RAVE collected moderate-resolution (R ~ 7500) spectra in the region of the Ca …
Radio-loud Quasars above Redshift 4: Very Long Baseline Interferometry (VLBI) Imaging of an Extended Sample
Paragi, Zsolt; Krezinger, Máté; Frey, Sándor +7 more
High-redshift radio sources provide plentiful opportunities for studying the formation and evolution of early galaxies and supermassive black holes. However, the number of known radio-loud active galactic nuclei (AGN) above redshift 4 is rather limited. At high redshifts, it appears that blazars, with relativistically beamed jets pointing toward t…
Stellar Atmospheric Parameters of M-type Stars from LAMOST DR8
Gao, Qi; Wu, Yue; Yan, Hong-Liang +9 more
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Low Resolution Spectroscopic Survey (LRS) provides massive spectroscopic data on M-type stars, and the derived stellar parameters could bring vital help to various studies. We adopt the ULySS package to perform χ 2 minimization with model spectra generated from the M…
A Bayesian Analysis of Physical Parameters for 783 Kepler Close Binaries: Extreme-mass-ratio Systems and a New Mass Ratio versus Period Lower Limit
Kobulnicky, Henry A.; Cook, Evan M.; Molnar, Lawrence A. +1 more
Contact binary star systems represent the long-lived penultimate phase of binary evolution. Population statistics of their physical parameters inform an understanding of binary evolutionary pathways and end products. We use light curves and new optical spectroscopy to conduct a pilot study of ten (near) contact systems in the long-period (P > 0…
Universal Scaling Laws for Solar and Stellar Atmospheric Heating: Catalog of Power-law Index between Solar Activity Proxies and Various Spectral Irradiances
Notsu, Yuta; Namekata, Kosuke; Toriumi, Shin +1 more
The formation of extremely hot outer atmospheres is one of the most prominent manifestations of magnetic activity common to late-type dwarf stars, including the Sun. It is widely believed that these atmospheric layers, the corona, transition region, and chromosphere, are heated by the dissipation of energy transported upwards from the stellar surf…
Finding Quasars behind the Galactic Plane. II. Spectroscopic Identifications of 204 Quasars at ∣b∣ < 20°
Zheng, Jie; Jiang, Linhua; Feng, Xiaotong +21 more
Quasars behind the Galactic plane (GPQs) are important astrometric references and valuable probes of Galactic gas, yet the search for GPQs is difficult due to severe extinction and source crowding in the Galactic plane. In this paper, we present a sample of 204 spectroscopically confirmed GPQs at ∣b∣ < 20°, 191 of which are new discoveries. Thi…
A Catalog of Early-type Hα Emission-line Stars and 62 Newly Confirmed Herbig Ae/Be Stars from LAMOST Data Release 7
Qin, Li; Luo, A. -Li; Hou, Wen +6 more
We derive a catalog of early-type emission-line stars including 30,023 spectra of 25,867 stars from LAMOST Data Release 7, in which 4189 have Simbad records. The spectra are classified into three morphological types (10 subtypes) based on Hα emission-line profiles. Some spectra contaminated by nebula emission lines such as from H II regions are fl…
BASS. XXIII. A New Mid-infrared Diagnostic for Absorption in Active Galactic Nuclei
Ricci, Claudio; Stern, Daniel; Trakhtenbrot, Benny +15 more
In this study, we use the Swift/BAT AGN sample, which has received extensive multiwavelength follow-up analysis as a result of the BAT AGN Spectroscopic Survey, to develop a diagnostic for nuclear obscuration by examining the relationship between the line-of-sight column densities (N H), the 2–10 keV to 12 µm luminosity ratio, and…
Photometric Recalibration of the SDSS Stripe 82 to a Few Millimagnitude Precision with the Stellar Color Regression Method and Gaia EDR3
Huang, Bowen; Yuan, Haibo
By combining spectroscopic data from the LAMOST DR7, Sloan Digital Sky Survey (SDSS) DR12, and corrected photometric data from the Gaia EDR3, we apply the stellar color regression (SCR) method to recalibrate the SDSS Stripe 82 standard stars catalog of Ivezić et al. With a total number of about 30,000 spectroscopically targeted stars, we have mapp…