Search Publications
Star formation in the nearby dwarf galaxy DDO 53: interplay between gas accretion and stellar feedback
Egorov, Oleg V.; Lozinskaya, Tatiana A.; Vasiliev, Konstantin I. +4 more
We present the results of a multiwavelength study of the nearby dwarf galaxy DDO 53 - a relatively isolated member of the M 81 group. We analyse the atomic and ionized gas kinematics (based on the observations with Fabry-Perot interferometer in H α line and archival data in H I 21 cm line), distribution, excitation, and oxygen abundance of the ion…
The McDonald Accelerating Stars Survey (MASS): Discovery of a Long-period Substellar Companion Orbiting the Old Solar Analog HD 47127
Cochran, William D.; Endl, Michael; Crepp, Justin R. +12 more
Brown dwarfs with well-determined ages, luminosities, and masses provide rare but valuable tests of low-temperature atmospheric and evolutionary models. We present the discovery and dynamical mass measurement of a substellar companion to HD 47127, an old (≈7-10 Gyr) G5 main-sequence star with a mass similar to the Sun. Radial velocities of the hos…
Three ultraluminous X-ray sources hosted by globular clusters in NGC 1316
Kundu, Arunav; Strader, Jay; Dage, Kristen C. +8 more
We have identified three ultraluminous X-ray sources (ULXs) hosted by globular clusters (GCs) within NGC 1316's stellar system. These discoveries bring the total number of known ULXs in GCs up to 20. We find that the X-ray spectra of the three new sources do not deviate from the established pattern of spectral behaviour of the other known GC ULXs.…
Further support for a trio of mass-to-light deviations in Abell 370: free-form GRALE lens inversion using BUFFALO strong lensing data
Koekemoer, Anton M.; Mahler, Guillaume; Acebron, Ana +9 more
We use the Beyond Ultra-deep Frontier Fields and Legacy Observations (BUFFALO) strong lensing image catalogue of the merging galaxy cluster Abell 370 to obtain a mass model using free-form lens inversion algorithm GRALE. The improvement of the strong lensing data quality results in a lens plane rms of only 0.45 arcsec, about a factor of two lower …
Testing the evolution of correlations between supermassive black holes and their host galaxies using eight strongly lensed quasars
Treu, Tommaso; Auger, Matthew W.; Birrer, Simon +9 more
One of the main challenges in using high-redshift active galactic nuclei (AGNs) to study the correlations between the mass of a supermassive black hole ($\mathcal {M}_{\rm BH}$) and the properties of its active host galaxy is instrumental resolution. Strong lensing magnification effectively increases instrumental resolution and thus helps to addre…
Tomography of the Unique Ongoing Jet in the Planetary Nebula NGC 2392
Guerrero, M. A.; Toalá, J. A.; Ramos-Larios, G. +5 more
Jets (fast collimated outflows) are claimed to be the main shaping agent of the most asymmetric planetary nebulae (PNs), as they impinge on the circumstellar material at late stages of the asymptotic giant branch phase. The first jet detected in a PN was that of NGC 2392, yet there is no available image because of its low surface brightness contra…
On the Nature of AGN and Star Formation Enhancement in the z = 3.1 SSA22 Protocluster: The HST WFC3 IR View
Kubo, Mariko; Umehata, Hideki; Alexander, David M. +9 more
We examine possible environmental sources of the enhanced star formation and active galactic nucleus (AGN) activity in the z = 3.09 SSA22 protocluster using Hubble WFC3 F160W (~1.6 µm) observations of the SSA22 field, including new observations centered on eight X-ray selected protocluster AGN. To investigate the role of mergers in the obser…
Photoionized Herbig-Haro Objects in the Orion Nebula through Deep High Spectral Resolution Spectroscopy. II. HH 204
Henney, W. J.; Méndez-Delgado, J. E.; Arellano-Córdova, K. Z. +3 more
We analyze the physical conditions, chemical composition, and other properties of the photoionized Herbig-Haro (HH) object HH 204 through Very Large Telescope echelle spectroscopy and Hubble Space Telescope imaging. We kinematically isolate the high-velocity emission of HH 204 from the emission of the background nebula and study the subarcsecond d…
A test of the planet-star unipolar inductor for magnetic white dwarfs
Hermes, J. J.; Marsh, T. R.; Bagnulo, S. +7 more
Despite thousands of spectroscopic detections, only four isolated white dwarfs exhibit Balmer emission lines. The temperature inversion mechanism is a puzzle over 30 years old that has defied conventional explanations. One hypothesis is a unipolar inductor that achieves surface heating via ohmic dissipation of a current loop between a conducting p…
Project MOMO: Multiwavelength Observations and Modeling of OJ 287
Ciprini, S.; Komossa, S.; Gallo, L. C. +9 more
Our project MOMO (Multiwavelength observations and modeling of OJ 287) consists of dedicated, dense, long-term flux and spectroscopic monitoring, and deep follow-up observations of the blazar OJ 287 at >13 frequencies from the radio to the X-ray band since late 2015. In particular, we are using Swift to obtain optical-UV-X-ray spectral energy d…