Search Publications
Limits to Rest-frame Ultraviolet Emission from Far-infrared-luminous z ≃ 6 Quasar Hosts
Jahnke, K.; Koekemoer, A. M.; Fan, X. +20 more
We report on a Hubble Space Telescope search for rest-frame ultraviolet emission from the host galaxies of five far-infrared-luminous z ≃ 6 quasars and the z = 5.85 hot-dust-free quasar SDSS J0005-0006. We perform 2D surface brightness modeling for each quasar using a Markov Chain Monte Carlo estimator, to simultaneously fit and subtract the quasa…
The Villafranca catalog of Galactic OB groups. I. Systems with O2-O3.5 stars
Maíz Apellániz, J.; Barbá, R. H.; Sota, A. +2 more
Context. The spectral classifications of the Galactic O-Star Spectroscopic Survey (GOSSS) and the astrometric and photometric data from Gaia have significantly improved our ability to measure distances and determine memberships of stellar groups (clusters, associations, or parts thereof) with OB stars. In the near future, the situation will be fur…
Blanco DECam Bulge Survey (BDBS) II: project performance, data analysis, and early science results
Clarkson, William I.; Kunder, Andrea; Johnson, Christian I. +7 more
The Blanco DECam Bulge Survey (BDBS) imaged more than 200 sq deg of the Southern Galactic bulge using the ugrizY filters of the Dark Energy Camera, and produced point spread function photometry of approximately 250 million unique sources. In this paper, we present details regarding the construction and collation of survey catalogues, and also disc…
Solving Grain Size Inconsistency between ALMA Polarization and VLA Continuum in the Ophiuchus IRS 48 Protoplanetary Disk
Henning, Thomas; Hull, Charles L. H.; Kataoka, Akimasa +6 more
The protoplanetary disk around Ophiuchus IRS 48 shows an azimuthally asymmetric dust distribution in (sub)millimeter observations, which is interpreted as a vortex, where millimeter/centimeter-sized particles are trapped at the location of the continuum peak. In this paper, we present 860 µm ALMA observations of polarized dust emission from …
Runaway OB Stars in the Small Magellanic Cloud: Dynamical versus Supernova Ejections
Oey, M. S.; Castro, N.; Moe, M. +2 more
Runaway OB stars are ejected from their parent clusters via two mechanisms, both involving multiple stars: the dynamical ejection scenario (DES) and the binary supernova scenario (BSS). We constrain the relative contributions from these two ejection mechanisms in the Small Magellanic Cloud (SMC) using data for 304 field OB stars from the spatially…
A First Spectroscopic Measurement of the Magnetic-field Strength for an Active Region of the Solar Corona
Brage, Tomas; Si, Ran; Li, Wenxian +3 more
For all involved in astronomy, the importance of monitoring and determining astrophysical magnetic-field strengths is clear. It is also a well-known fact that the corona magnetic fields play an important part in the origin of solar flares and the variations of space weather. However, after many years of solar corona studies, there is still no dire…
NICER Observation of the Temporal and Spectral Evolution of Swift J1818.0-1607: A Missing Link between Magnetars and Rotation-powered Pulsars
Enoto, Teruaki; Sakamoto, Takanori; Ray, Paul S. +13 more
We report on the hard X-ray burst and the first ∼100 days of NICER monitoring of the soft X-ray temporal and spectral evolution of the newly discovered magnetar Swift J1818.0-1607. The burst properties are typical of magnetars with a duration of T90 = 10 ± 4 ms and a temperature of kT = 8.4 ± 0.7 keV. The 2-8 keV pulse shows a broad, si…
Frequency of Planets in Binaries
Bonavita, Mariangela; Desidera, Silvano
The frequency of planets in binaries is an important issue in the field of extrasolar planet studies because of its relevance in the estimation of the global planet population of our galaxy and the clues it can give to our understanding of planet formation and evolution. Multiple stars have often been excluded from exoplanet searches, especially t…
Observed binary populations reflect the Galactic history. Explaining the orbital period-mass ratio relation in wide hot subdwarf binaries
Bobrick, A.; Vučković, M.; Vos, J.
Context. Wide hot subdwarf B (sdB) binaries with main-sequence companions are outcomes of stable mass transfer from evolved red giants. The orbits of these binaries show a strong correlation between their orbital periods and mass ratios. The origins of this correlation have, so far, been lacking a conclusive explanation.
Aims: We aim to find …
SuperBoRG: Exploration of Point Sources at z ∼ 8 in HST Parallel Fields
Treu, T.; Mason, C. A.; Trenti, M. +7 more
To extend the search for quasars in the epoch of reionization beyond the tip of the luminosity function, we explore point-source candidates at redshift z ∼ 8 in SuperBoRG, a compilation of ∼0.4 deg2 archival medium-deep (mF160W ∼ 26.5 ABmag, 5σ) parallel infrared (IR) images taken with the Hubble Space Telescope (HST). Initia…