Search Publications
Lyman Continuum Galaxy Candidates in COSMOS
Hathi, Nimish; Rafelski, Marc; Wang, Xin +11 more
Star-forming galaxies are the sources likely to have reionized the universe. As we cannot observe them directly due to the opacity of the intergalactic medium at z ≳ 5, we study z ~ 3-5 galaxies as proxies to place observational constraints on cosmic reionization. Using new deep Hubble Space Telescope rest-frame UV F336W and F435W imaging (30 orbi…
Generic profile of a long-lived corotating interaction region and associated recurrent Forbush decrease
Temmer, M.; Vršnak, B.; Dumbović, M. +2 more
Context. Corotating interaction regions (CIRs), formed by the interaction of slow solar wind and fast streams that originate from coronal holes (CHs), produce recurrent Forbush decreases, which are short-term depressions in the galactic cosmic ray (GCR) flux.
Aims: Our aim is to prepare a reliable set of CIR measurements to be used as a textb…
Large-scale expansion of OB stars in Cygnus
Quintana, Alexis L.; Wright, Nicholas J.
The proper motions (PMs) of OB stars in Cygnus have recently been found to exhibit two large-scale kinematic patterns suggestive of expansion. We perform a 3D traceback on these OB stars, the newly identified OB associations and related open clusters in the region. We find that there are two groups of stars, associations and clusters and that they…
Duality in spatially resolved star formation relations in local LIRGs
Colina, L.; Villar-Martín, M.; Arribas, S. +10 more
We analyse the star formation (SF) relations in a sample of 16 nearby luminous infrared galaxies (LIRGs) with more than 2800 regions defined on scales of 90 to 500 pc. We used ALMA to map the distribution of the cold molecular gas traced by the J = 2-1 line of CO and archival Paα HST/NICMOS imaging to trace the recent SF. In four objects we find t…
The case for an ocean-bearing Mimas from tidal heating analysis
Rhoden, Alyssa Rose; Walker, Matthew E.
Cassini measurements of Mimas' physical libration can be explained by either a non-hydrostatic core or a global, liquid water ocean beneath a 24-31 km thick ice shell. An ocean within Mimas would be surprising, given the lack of comparable geologic activity to that observed on other ocean-bearing moons like Europa and Enceladus, and thus has impor…
Revisiting KELT-19Ab, WASP-156b, and WASP-121b in the TESS Era
Chary, Ranga-Ram; Yang, Fan; Liu, Ji-Feng
We present a re-analysis of transit depths of KELT-19Ab, WASP-156b, and WASP-121b, including data from the Transiting Exoplanet Survey Satellite (TESS). The large ~21″ TESS pixels and point-spread function result in significant contamination of the stellar flux by nearby objects. We use Gaia data to fit for and remove this contribution, providing …
A Strong Shock During a Nova Outburst: An Origin of Multiple Velocity Systems in Optical Spectra and of High-energy Emissions
Kato, Mariko; Hachisu, Izumi
We propose a theoretical explanation of absorption/emission line systems in classical novae based on a fully self-consistent nova explosion model. We found that a reverse shock is formed far outside the photosphere (≳1013 cm) because later-ejected mass with a faster velocity collides with earlier-ejected matter. Optically thick winds bl…
A Bayesian Analysis of Physical Parameters for 783 Kepler Close Binaries: Extreme-mass-ratio Systems and a New Mass Ratio versus Period Lower Limit
Kobulnicky, Henry A.; Cook, Evan M.; Molnar, Lawrence A. +1 more
Contact binary star systems represent the long-lived penultimate phase of binary evolution. Population statistics of their physical parameters inform an understanding of binary evolutionary pathways and end products. We use light curves and new optical spectroscopy to conduct a pilot study of ten (near) contact systems in the long-period (P > 0…
Metallicities and ages for star clusters and their surrounding fields in the Large Magellanic Cloud
Smolec, R.; Piatti, A. E.; Lewis, M. O. +15 more
Aims: We study 147 star clusters in the Large Magellanic Cloud (LMC) in order to determine their mean metallicities and ages, as well as the mean metallicities of 80 surrounding fields. We construct an age-metallicity relation (AMR) for the clusters in the LMC.
Methods: For this purpose, we used Strömgren photometry obtained with the SOI…
Discovery, Timing, and Multiwavelength Observations of the Black Widow Millisecond Pulsar PSR J1555-2908
Ransom, Scott M.; Michelson, P. F.; Halpern, Jules P. +21 more
We report the discovery of PSR J1555-2908, a 1.79 ms radio and gamma-ray pulsar in a 5.6 hr binary system with a minimum companion mass of 0.052 M ⊙. This fast and energetic ( $\dot{E}=3\times {10}^{35}$ erg s-1) millisecond pulsar was first detected as a gamma-ray point source in Fermi Large Area Telescope (LAT) sky survey o…