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Rotating Solar Models in Agreement with Helioseismic Results and Updated Neutrino Fluxes
Yang, Wuming
Standard solar models (SSMs) constructed in accordance with old solar abundances are in reasonable agreement with seismically inferred results, but SSMs with new low-metal abundances disagree with the seismically inferred results. The constraints of neutrino fluxes on solar models exist in parallel with those of helioseismic results. The solar neu…
Demographics of the M-star Multiple Population in the Orion Nebula Cluster
Reiter, Megan; Meyer, Michael R.; De Furio, Matthew +4 more
We present updated results constraining multiplicity demographics for the stellar population of the Orion Nebula Cluster (ONC, a high-mass, high-density star-forming region), across primary masses 0.08-0.7 M ⊙. Our study utilizes archival Hubble Space Telescope data obtained with the Advanced Camera for Surveys using multiple filters (G…
The Long Stare at Hercules X-1. I. Emission Lines from the Outer Disk, the Magnetosphere Boundary, and the Accretion Curtain
Fabian, A. C.; Reynolds, C. S.; Pinto, C. +11 more
Hercules X-1 is a nearly edge-on accreting X-ray pulsar with a warped accretion disk, precessing with a period of about 35 days. The disk precession allows for unique and changing sightlines toward the X-ray source. To investigate the accretion flow at a variety of sightlines, we obtained a large observational campaign on Her X-1 with XMM-Newton (…
Thermal Comptonization in a Changing Corona in the Changing-look Active Galaxy NGC 1566
Dewangan, Gulab Chand; Tripathi, Prakash
We present broadband UV/X-ray spectral variability of the changing-look active galactic nucleus (AGN) NGC 1566, based on simultaneous near-ultraviolet and X-ray observations performed by the XMM-Newton, Swift, and NuSTAR satellites at five different epochs during the declining phase of the 2018 outburst. We found that the accretion disk, soft X-ra…
Estimating the Ages of Open Star Clusters from Properties of Their Extended Tidal Tails
Kroupa, Pavel; Jeřábková, Tereza; Šubr, Ladislav +1 more
The most accurate current methods for determining the ages of open star clusters, stellar associations, and stellar streams are based on isochrone fitting or the lithium depletion boundary. We propose another method for dating these objects based on the morphology of their extended tidal tails, which have been recently discovered around several op…
Mid- and Far-infrared Color-Color Relations within Local Galaxies
Calzetti, Daniela; Heyer, Mark; Gregg, Benjamin
We present an extensive archival analysis of a sample of local galaxies, combining multiwavelength data from GALEX, Spitzer, and Herschel to investigate "blue-side" mid-infrared (MIR) and "red-side" far-infrared (FIR) color-color correlations within the observed infrared spectral energy distributions. Our sample largely consists of the KINGFISH ga…
Molecular and Atomic Clouds Associated with the Gamma-Ray Supernova Remnant Puppis A
Rowell, G.; Fukui, Y.; Reynoso, E. M. +3 more
We have carried out a study of the interstellar medium (ISM) toward the shell-like supernova remnant (SNR) Puppis A using NANTEN CO and ATCA H I data. We synthesized a comprehensive picture of the SNR radiation by combining the ISM data with the gamma-ray and X-ray distributions. The ISM, both atomic and molecular gas, is dense and highly clumpy, …
Hubble Space Telescope Observations of Active Asteroid P/2020 O1 (Lemmon-PANSTARRS)
Mutchler, Max; Jewitt, David; Agarwal, Jessica +3 more
We present Hubble Space Telescope observations of active asteroid P/2020 O1 taken to examine its development for a year after perihelion. We find that the mass loss peaks at ≲1 kg s-1 in 2020 August and then declines to nearly zero over four months. Long-duration mass loss (~180 days) is consistent with a sublimation origin, indicating …
Chemical Properties of the Local Disk and Halo. II. Abundances of 3745 M Dwarfs and Subdwarfs from Improved Model Fitting of Low-resolution Spectra
Nordlander, Thomas; Lépine, Sébastien; Hejazi, Neda
We present a model-fit pipeline to determine the stellar parameters of M-type dwarfs, which is an improvement on our previous work described in Hejazi et al. We apply this pipeline to analyze the low-resolution (R ~ 2000) spectra of 3745 M dwarfs/subdwarfs, collected at the MDM Observatory, Lick Observatory, Kitt Peak National Observatory, and Cer…
Solar Toroidal Field Evolution Spanning Four Sunspot Cycles Seen by the Wilcox Solar Observatory, the Solar and Heliospheric Observatory/Michelson Doppler Imager, and the Solar Dynamics Observatory/Helioseismic and Magnetic Imager
Scherrer, Philip H.; Liu, Allison L.
Forty-four years of Wilcox Solar Observatory, 14 years of Michelson Doppler Imager on the Solar and Heliospheric Observatory, and 11 years of Helioseismic and Magnetic Imager on the Solar Dynamics Observatory magnetic field data have been studied to determine the east-west inclination-the toroidal component-of the magnetic field. Maps of the zonal…