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Circumnuclear Rings and Lindblad Resonances in Spiral Galaxies
Díaz, R. J.; Agüero, M. P.; Gaspar, G. +5 more
In order to study the location of circumnuclear rings (CNR) and their possible relation with the inner Lindblad resonances (ILR), we investigate a sample of spiral galaxies. For this purpose, we have obtained and analyzed medium resolution spectra of five spiral galaxies in the range 6200-6900 Å. Through the Hα emission line, we constructed the ra…
Photometric and Spectral Observations of the W UMa Stars NSVS 4161544 and 1SWASP J034501.24+493659.9. GAIA Challenges
Kjurkchieva, Diana; Popov, Velimir A.; Stateva, Ivanka +1 more
Photometric and spectral observations of the W UMa binaries NSVS 4161544 and 1SWASP J034501.24+493659.9 with periods of around 8 hr are presented. The simultaneous light-curve and radial-velocity-curve solutions revealed that the two targets have over-contact configurations, and their components undergo partial eclipses. The derived parameters of …
Time-series Spectroscopy of the Oscillating Eclipsing Algol System V392 Orionis
Koo, Jae-Rim; Han, Cheongho; Kim, Seung-Lee +5 more
We present the results from a detailed analysis of our high-resolution spectra and historical photometric observations of the semidetached eclipsing binary V392 Ori with a δ Scuti (δ Sct) pulsating component. A total of 31 spectroscopic observations were carried out at both the Bohyunsan Optical Astronomy Observatory in Korea and the Thai National…
The Composite Nature of Dust-obscured Galaxies (DOGs) at z ∼ 2-3 in the COSMOS Field. II. The AGN Fraction
Koekemoer, Anton M.; Schawinski, Kevin; Lusso, Elisabeta +18 more
We present the X-ray properties of 108 Dust-Obscured Galaxies (DOGs; F 24 µm/F R > 1000) in the COSMOS field, all of which are detected in at least three far-infrared bands with the Herschel Observatory. Out of the entire sample, 22 are individually detected in the hard 2-8 keV X-ray band by the Chandra COSMOS Lega…
The G305 Star-forming Region. I. Newly Classified Hot Stars
Kounkel, Marina; Minniti, Dante; Stringfellow, Guy +12 more
The relatively nearby star-forming complex G305 is one of the most luminous H II regions in the Galaxy, and it contains several sites and epochs of star formation. Using a combination of near-infrared photometry from “Vista Variables in Via Lactea” ESO Large Public Survey, SDSS-IV APOGEE-2 spectra, and Gaia DR2 photometry and astrometry, we report…
Colors of Trans-Neptunian Contact Binaries
Thirouin, Audrey; Sheppard, Scott S.
The g‧r‧i‧ colors of seven likely and potential contact binaries in the Kuiper Belt were acquired with the Magellan-Baade telescope and combined with colors from the literature to understand contact binary surfaces. The likely and potential contact binaries discovered in the dynamically cold classical population display very red/ultra-red colors. …
A Radial Velocity Survey of Embedded Sources in the Rho Ophiuchi Cluster
Greene, Thomas P.; Gibb, Erika L.; Wilking, Bruce A. +3 more
We present the results of a radial velocity survey of young stellar objects (YSOs) in early stages of evolution in the core of the L1688 molecular cloud. New and archival spectra obtained with four high-resolution infrared spectrographs were analyzed using Markov chain Monte Carlo techniques that simultaneously fit for the radial velocity, T …
OGLE-2018-BLG-0022: A Nearby M-dwarf Binary
Saha, A.; Lowry, S.; Mao, S. +32 more
We report observations of the binary microlensing event OGLE-2018-BLG-0022, provided by the Robotic Observations of Microlensing Events (ROME)/Reactive Event Assessment (REA) Survey, which indicate that the lens is a low-mass binary star consisting of M3 (0.375 ± 0.020 M ⊙) and M7 (0.098 ± 0.005 M ⊙) components. The lens is u…
New Insights into Interstellar Object 1I/2017 U1 (‘Oumuamua) from SOHO/STEREO Nondetections
Knight, Matthew M.; Hui, Man-To
Object 1I/2017 U1 (‘Oumuamua) is the first interstellar small body ever discovered in the solar system. By the time of discovery, it had already passed perihelion. To investigate the behavior of ‘Oumuamua around perihelion, we searched for it in Solar and Heliospheric Observatory (SOHO) and Solar TErrestrial RElations Observatory (STEREO) images f…
Analysis of a Century’s Worth of AR Scorpii Photometry from DASCH and ASAS-SN
Garnavich, Peter; Littlefield, Colin; Peterson, Erik
AR Scorpii (AR Sco) is a binary star system containing the only known white dwarf (WD) pulsar. Previously reported photometric data sets only provide coverage back to 2005, but we extend the observational baseline for AR Sco back to the beginning of the 20th century by analyzing observations from the Digital Access to a Sky Century at Harvard proj…