Search Publications
A CO-to-H2 Ratio of ≈10-5 toward the Herbig Ae Star HK Ori
France, Kevin; Johns-Krull, Christopher M.; Cauley, P. Wilson +1 more
Measurements of gas mass in protoplanetary gas disks form the basis for estimating the conditions of planet formation. Among the most important constraints derived from disk diagnostics are the abundances of gas-phase species critical for understanding disk chemistry. Toward this end, we present direct line-of-sight measurements of H2 a…
The first light curve solutions and period study of two contact binary systems: V1370 Tau and QQ Boo
Davoudi, Fatemeh; Poro, Atila; Rahimi, Jabar +7 more
The first light curve solutions of the binary systems V1370 Tau and QQ Boo are presented. The periodic changes are calculated, and a new ephemeris presented for each of these two binary systems. O-C analysis is performed using the MCMC method in OCFit code. The changing rate of period was measured as dP/dt= 0.2423 days/year for V1370 Tau and dP/dt…
Extremely Low Molecular Gas Content in the Vicinity of a Red Nugget Galaxy at z = 1.91
Stiavelli, M.; Lucas, R. A.; D'Amato, Q. +3 more
We present Atacama Large Millimeter/submillimeter Array Band 5 observations of a galaxy at z = 1.91, GDS24569, in search of molecular gas in its vicinity via the [C I] 3P1-3P0 line. GDS24569 is a massive ( $\mathrm{log}{M}_{* }/{M}_{\odot }=11$ ), passively evolving galaxy, characterized by compact morph…
Study of UV-bright stellar populations in the globular cluster NGC 1261 using Astrosat
Rao, N. Kameswara; Sahu, Snehalata; Subramaniam, Annapurni +2 more
We present UV photometry of the globular cluster NGC 1261 using images acquired with the Ultraviolet Imaging Telescope (UVIT) on board Astrosat. We performed point-spread function (PSF) photometry on four near-UV (NUV) and two far-UV (FUV) images and constructed UV colour-magnitude diagrams (CMDs), in combination with the Hubble Space Telescope (H…
Was Gale Crater (Mars) Connected to a Regionally Extensive Groundwater System?
Horvath, D. G.; Roseborough, V.; Palucis, M. C.
Gale crater, home of the Curiosity rover, contains some of the best geomorphic and sedimentologic evidence on Mars for large lakes during the Hesperian and Amazonian. Orbital data and rover observations of delta deposits and terminations of gully networks suggest several phases of stable lake levels. However, the regional extent, water source (gro…
Arm Tangents and the Spiral Structure of the Milky Way—The Age Gradient
Vallée, Jacques P.
From the Sun, a look at the edge of each spiral arm in our Milky Way (seen tangentially, along the line of sight) can yield numerous insights. Using different arm tracers (dust, masers, synchrotron emission, CO gas, open star clusters), we observe here for the first time an age gradient (about 12 +/-2 Myrs/kpc), much as predicted by the density wa…
Wide band, tunable gamma-ray lenses
Lund, Niels
A new concept for an astronomical telescope in the MeV energy band is presented. The concept builds on Bragg diffraction in crystals, which has been discussed in the past, but so far a design with good sensitivity over a wide energy range has seemed out of reach. In this paper we point out that if we find ways to adjust, in orbit, the individual t…
Physical Characterization of Serendipitously Uncovered Millimeter-wave Line-emitting Galaxies at z 2.5 behind the Local Luminous Infrared Galaxy VV 114
Tamura, Yoichi; Kohno, Kotaro; Yun, Min S. +11 more
We present a detailed investigation of millimeter-wave line emitters ALMA J010748.3-173028 (ALMA-J0107a) and ALMA J010747.0-173010 (ALMA-J0107b), which were serendipitously uncovered in the background of the nearby galaxy VV 114 with spectral scan observations at λ = 2-3 mm. Via Atacama Large Millimeter/submillimeter Array (ALMA) detection of CO(4…
Evolution of Saturn's north polar color and cloud structure between 2012 and 2017 inferred from Cassini VIMS and ISS observations
Baines, K. H.; Sromovsky, L. A.; Fry, P. M.
Cassini/ISS imagery and Cassini/VIMS spectral imaging observations from 0.35 to 5.12 µm show that Saturn's north polar region (70 °-90 ° N) evolved significantly between 2012 and 2017, with the region poleward of the hexagon changing from dark blue/green to a moderately brighter gold color, except for the inner eye region (88.2 °-90 ° N), wh…
ALMA Observations of the Inner Cavity in the Protoplanetary Disk around Sz 84
Dong, Ruobing; Tamura, Motohide; Takami, Michihiro +5 more
We present Atacama Large Millimeter/submillimeter Array observations of a protoplanetary disk around the T Tauri star Sz 84 and analyses of the structures of the inner cavity in the central region of the dust disk. Sz 84's spectral energy distribution (SED) has been known to exhibit negligible infrared excess at λ ≲ 10 µm due to the disk's c…