Search Publications
Variable Stars in the Giant Satellite Galaxy Antlia 2
Erkal, Denis; Belokurov, Vasily; Li, Ting S. +3 more
We report 350 pulsating variable stars found in four DECam fields (~12 deg2) covering the Antlia 2 satellite galaxy. The sample of variables includes 318 RR Lyrae stars and eight anomalous Cepheids in the galaxy. Reclassification of several objects designated previously to be RR Lyrae as anomalous Cepheids get rid of the satellite's sta…
Pearls on a String: Numerous Stellar Clusters Strung Along the Same Orbit
Rix, Hans-Walter; Fürnkranz, Verena; Coronado, Johanna
Stars originate from the dense interstellar medium, which exhibits filamentary structure to scales of ~1 kpc in galaxies like our Milky Way. We explore quantitatively how much resulting large-scale correlation there is among different stellar clusters and associations in orbit-phase space, characterized here by actions and angles. As a starting po…
Galactic Cosmic-Ray Propagation in the Inner Heliosphere: Improved Force-field Model
Peter, Annika H. G.; Beacom, John F.; Li, Jung-Tsung
A key goal of heliophysics is to understand how cosmic rays propagate in the solar system's complex, dynamic environment. One observable is solar modulation, i.e., how the flux and spectrum of cosmic rays change as they propagate inward. We construct an improved force-field model, taking advantage of new measurements of magnetic power spectral den…
The Ultramassive White Dwarfs of the Alpha Persei Cluster
Caiazzo, Ilaria; Richer, Harvey B.; Heyl, Jeremy +2 more
We searched through the entire Gaia EDR3 candidate white dwarf catalog for stars with proper motions and positions that are consistent with them having escaped from the Alpha Persei cluster within the past 81 Myr, the age of the cluster. In this search we found five candidate white dwarf escapees from Alpha Persei and obtained spectra for all of t…
Structural Parameters and Possible Association of the Ultra-faint Dwarfs Pegasus III and Pisces II from Deep Hubble Space Telescope Photometry
Choi, Yumi; van der Marel, Roeland P.; Geha, Marla +17 more
We present deep Hubble Space Telescope (HST) photometry of the ultra-faint dwarf (UFD) galaxies Pegasus III (Peg III) and Pisces II (Psc II), two of the most distant satellites in the halo of the Milky Way (MW). We measure the structure of both galaxies, derive mass-to-light ratios with newly determined absolute magnitudes, and compare our finding…
Validation of a Wave Heated 3D MHD Coronal-wind Model using Polarized Brightness and EUV Observations
Pinto, Rui F.; Réville, Victor; Strugarek, Antoine +5 more
The physical properties responsible for the formation and evolution of the corona and heliosphere are still not completely understood. 3D MHD global modeling is a powerful tool to investigate all the possible candidate processes. To fully understand the role of each of them, we need a validation process where the output from the simulations is qua…
New Time-resolved, Multi-band Flares in the GJ 65 System with gPhoton
Brasseur, C. E.; Osten, Rachel A.; Fleming, Scott W. +2 more
Characterizing the distribution of flare properties and occurrence rates is important for understanding habitability of M-dwarf exoplanets. The Galaxy Evolution Explorer (GALEX) space telescope observed the GJ 65 system, composed of the active, flaring M stars BL Cet and UV Cet, for 15,900 s (~4.4 hr) in two ultraviolet (UV) bands. The contrast in…
A Mass Model for the Lensing Cluster SDSS J1004+4112: Constraints from the Third Time Delay
Kochanek, C. S.; Muñoz, J. A.; Mediavilla, E. +1 more
We have built a new model for the lens system SDSS J1004+4112 including the recently measured time delay of the fourth quasar image. This time delay has a strong influence on the inner mass distribution of the lensing cluster (ρ ∝ r -α ) allowing us to determine $\alpha ={1.18}_{-0.03(-0.18)}^{+0.02(+0.11)}$ at the 68% (95%) confidence …
A Multiwavelength View of IC 860: What Is in Action inside Quenching Galaxies
Heckman, Timothy; Aalto, Susanne; French, K. Decker +15 more
We present a multiwavelength study of IC 860, a nearby post-starburst galaxy at the early stage of transitioning from blue and star forming to red and quiescent. Optical images reveal a galaxy-wide, dusty outflow originating from a compact core. We find evidence for a multiphase outflow in the molecular and neutral gas phase from the CO position-v…
Lyα Halos around [O III]-selected Galaxies in HETDEX
Finkelstein, Steven L.; Schneider, Donald P.; Gebhardt, Karl +13 more
We present extended Lyα emission out to 800 kpc of 1034 [O III]-selected galaxies at redshifts 1.9 < z < 2.35 using the Hobby-Eberly Telescope Dark Energy Experiment. The locations and redshifts of the galaxies are taken from the 3D-HST survey. The median-stacked surface brightness profile of the Lyα emission of the [O III]-selected galaxies…