Search Publications
On the Connection between Solar Surface Magnetic Flux and the Total Solar Irradiance
Gopalswamy, N.; Tessema, S. B.; Shukure, N. T.
Solar surface magnetic flux evolution plays a dominant role in the variability of total solar irradiance (TSI). Different proxies of magnetic activity have been introduced to correlate solar variability and TSI. We present the daily strong flux densities (SFDs) and weak flux densities (WFDs) defined with three magnetic thresholds calculated from t…
Connecting Atmospheric Properties and Synthetic Emission of Shock Waves Using 3D RMHD Simulations of the Quiet Sun
Kosovichev, Alexander G.; Sadykov, Viacheslav M.; Kitiashvili, Irina N. +1 more
We analyze the evolution of shock waves in high-resolution 3D radiative MHD simulations of the quiet Sun and their synthetic emission characteristics. The simulations model the dynamics of a 12.8 × 12.8 × 15.2 Mm quiet-Sun region (including a 5.2 Mm layer of the upper convection zone and a 10 Mm atmosphere from the photosphere to corona) with an i…
Dissecting the Strong-lensing Galaxy Cluster MS 0440.5+0204. II. New Optical Spectroscopic Observations in a Wider Area and Cluster Dynamical State
Limousin, Marceau; Carrasco, Eleazar R.; Ellingson, E. +5 more
We present an optical study of the strong-lensing galaxy cluster MS 0440.5+0204 at z = 0.19593, based on CFHT/MegaCam g', r' photometry and GMOS/Gemini and CFHT/MOS/SIS spectroscopy in a broader area than previous works. We have determined new spectroscopic redshifts for the most prominent gravitational arcs surrounding the central galaxy in the c…
The Occurrence-weighted Median Planets Discovered by Transit Surveys Orbiting Solar-type Stars and Their Implications for Planet Formation and Evolution
Schlaufman, Kevin C.; Halpern, Noah D.
Since planet occurrence and primordial atmospheric retention probability increase with period, the occurrence-weighted median planets discovered by transit surveys may bear little resemblance to the low-occurrence, short-period planets sculpted by atmospheric escape ordinarily used to calibrate mass-radius relations and planet formation models. An…
The Unusual Weak-line Quasar PG1407+265 and Its Foreground z 0.7 X-Ray Cluster
McDowell, Jonathan C.; Gallo, Luigi C.; Siemiginowska, Aneta +2 more
We present new observations of the odd z = 0.96 weak-line quasar PG1407+265, and report the discovery of CXOU J140927.9+261813, a z = 0.68 X-ray cluster. Archival X-ray photometry spanning nearly four decades reveals that PG1407+265 is variable at the 1 dex level on a timescale of years. V-band variability is observed with an amplitude less than 0…
The Evolution of the Luminosity Function for Luminous Compact Blue Galaxies to z = 1
Pisano, D. J.; Bershady, M. A.; Crawford, S. M. +2 more
Luminous compact blue galaxies (LCBGs) are compact, star-forming galaxies that are rarely observed in the local universe but abundant at z = 1. This increase in LCBG number density over cosmic lookback time roughly follows the increase in the star formation rate density of the universe over the same period. We use publicly available data in the CO…
The Thermal Reprocessing of Reflected Radiation in the AGN Accretion Disk
Wang, Jiancheng; Zhong, Xiaogu
We present a reflected reprocessing model to study the thermal lag-wavelength relationship in the AGN accretion disk. The main radiation produced from the corona assumed with the lamppost geometry on the axis of the black hole irradiates the accretion disk to affect the temperature structure via reflection processes. Considering the thermal emissi…
Dark X-Ray Galaxies in the A1367 Galaxy Cluster
Henriksen, Mark J.; Dusek, Scott
We have characterized a sample of extended X-ray sources in the A1367 galaxy cluster that lack optical counterparts. The sources are galaxy size and have an average total mass of 1.3 × 1011 solar masses. The average hot gas mass is 3.0 × 109 solar masses and the average X-ray luminosity is 4.3 × 1041 erg cm-2<…
Anomalous Hα Emission Line Profile Detected at the Center of DDO 53
McQuinn, Kristen B. W.; van Zee, Liese; Hunter, Laura C. +1 more
We present the detection of a very broad (FWHM = 670 ± 17 km s-1), low-intensity Hα emission line component near the center of DDO 53, a star-forming dwarf irregular galaxy located in the M81 group. The broad component is found at the base of a bright and narrow (FWHM = 38 ± 2 km s-1) component. Using WIYN/Sparsepak optical s…
The Milky Way Project: Probing Star Formation with First Results on Yellowballs from DR2
Wolf-Chase, Grace; Kerton, C. R.; Devine, Kathryn +7 more
Yellowballs (YBs) were first discovered during the Milky Way Project (MWP) citizen science initiative. The MWP users noticed compact, yellow regions in Spitzer Space Telescope mid-infrared (MIR) images of the Milky Way plane and asked professional astronomers to explain these "yellow balls." Follow-up work by Kerton et al. determined that YBs like…