Search Publications
LEGUS and Hα-LEGUS Observations of Star Clusters in NGC 4449: Improved Ages and the Fraction of Light in Clusters as a Function of Age
Grebel, Eva K.; Smith, Linda J.; Aloisi, Alessandra +17 more
We present a new catalog and results for the cluster system of the starburst galaxy NGC 4449, based on multiband imaging observations taken as part of the LEGUS and Hα-LEGUS surveys. We improve the spectral energy fitting method used to estimate cluster ages, and find that the results, particularly for older clusters, are in better agre…
Probing the Nature of High-redshift Weak Emission Line Quasars: A Young Quasar with a Starburst Host Galaxy
Neeleman, Marcel; Walter, Fabian; Simcoe, Robert A. +15 more
We present the discovery of PSO J083.8371+11.8482, a weak emission line quasar with extreme star formation rate at z = 6.3401. This quasar was selected from Pan-STARRS1, UHS, and unWISE photometric data. Gemini/GNIRS spectroscopy follow-up indicates a Mg II-based black hole mass of ${M}_{\mathrm{BH}}=\left({2.0}_{-0.4}^{+0.7}\right)\times {10}^{9}…
Retrieval of the d/sdL7+T7.5p Binary SDSS J1416+1348AB
Gonzales, Eileen C.; Marley, Mark S.; Faherty, Jacqueline K. +5 more
We present the distance-calibrated spectral energy distribution (SED) of the d/sdL7 SDSS J14162408+1348263A (J1416A) and an updated SED for SDSS J14162408+1348263B (J1416B). We also present the first retrieval analysis of J1416A using the Brewster retrieval code base and the second retrieval of J1416B. We find that the primary is best fit by a non…
Internal motions in OB associations with Gaia DR2
Melnik, A. M.; Dambis, A. K.
We study the motions inside 28 OB associations with the use of Gaia DR2 proper motions. The average velocity dispersion calculated for 28 OB associations including more than 20 stars with Gaia DR2 proper motion is σV = 4.5 km s-1. The median virial and stellar masses of OB associations are Mvir = 8.9 × 105
The CO-dark molecular gas mass in 30 Doradus
Lebouteiller, Vianney; Lee, Min-Young; Kruijssen, J. M. Diederik +16 more
Determining the efficiency with which gas is converted into stars in galaxies requires an accurate determination of the total reservoir of molecular gas mass. However, despite being the most abundant molecule in the Universe, H2 is challenging to detect through direct observations and indirect methods have to be used to estimate the tot…
MIRACLES: atmospheric characterization of directly imaged planets and substellar companions at 4-5 µm. II. Constraints on the mass and radius of the enshrouded planet PDS 70 b
Quanz, S. P.; Todorov, K. O.; Stolker, T. +4 more
The circumstellar disk of PDS 70 hosts two forming planets, which are actively accreting gas from their environment. The physical and chemical characteristics of these planets remain ambiguous due to their unusual spectral appearance compared to more evolved objects. In this work, we report the first detection of PDS 70 b in the Brα and M' filters…
The composition and structure of Enceladus' plume from the complete set of Cassini UVIS occultation observations
Hansen, C. J.; Hendrix, A. R.; West, R. A. +4 more
Observations acquired at ultraviolet wavelengths are uniquely well-suited to investigate the composition and structure of Enceladus' plume. This paper describes the observations, analysis techniques and results of all the Enceladus occultations observed by Cassini's Ultraviolet Imaging Spectrograph (UVIS) and other observations designed to study t…
Estimation of the Physical Parameters of a CME at High Coronal Heights Using Low-frequency Radio Observations
Vourlidas, Angelos; Mondal, Surajit; Oberoi, Divya
Measuring the physical parameters of coronal mass ejections (CMEs), particularly their entrained magnetic field, is crucial for understanding their physics and for assessing their geoeffectiveness. At the moment, only remote sensing techniques can probe these quantities in the corona, the region where CMEs form and acquire their defining character…
Dynamical Evidence of a Spiral Arm-driving Planet in the MWC 758 Protoplanetary Disk
Debes, John H.; Schneider, Glenn; Esposito, Thomas M. +22 more
More than a dozen young stars host spiral arms in their surrounding protoplanetary disks. The excitation mechanisms of such arms are under debate. The two leading hypotheses—companion-disk interaction and gravitational instability (GI)—predict distinct motion for spirals. By imaging the MWC 758 spiral arm system at two epochs spanning ∼5 yr using …
Evidence for metallicity-dependent spin evolution in the Kepler field
Amard, Louis; Roquette, Julia; Matt, Sean P.
A curious rotation period distribution in the colour-magnitude-period diagram (CMPD) of the Kepler field was recently revealed, thanks to data from Gaia and Kepler spacecraft. It was found that redder and brighter stars are spinning slower than the rest of the main sequence. On the theoretical side, it was demonstrated that metallicity should affe…