Search Publications
A Rapidly Accreting Active Galactic Nucleus Hidden in a Dust-obscured Galaxy at z ∼ 0.8
Brandt, William N.; Yu, Zhibo; Zou, Fan +3 more
Dust-obscured galaxies (DOGs) containing central supermassive black holes (SMBHs) that are rapidly accreting (i.e., having high Eddington ratios, λ Edd) may represent a key phase closest to the peak of both the black hole and galaxy growth in the coevolution framework for SMBHs and galaxies. In this work, we present a 68 ks XMM-Newton o…
X-ray observations of Blueberry galaxies
Zezas, A.; Petrucci, P. -O.; Boorman, P. G. +7 more
Context. Compact star-forming galaxies were dominant galaxy types in the early Universe. Blueberry galaxies (BBs) represent their local analogues, being very compact and having intense star formation. Aims. Motivated by high X-ray emission recently found in other analogical dwarf galaxies, called Green Peas, we probed the X-ray properties of BBs t…
Distance Estimate Method for Asymptotic Giant Branch Stars Using Infrared Spectral Energy Distributions
Stroh, Michael C.; Sahai, Raghvendra; Sjouwerman, Loránt O. +8 more
We present a method to estimate distances to asymptotic giant branch (AGB) stars in the Galaxy, using spectral energy distributions (SEDs) in the near- and mid-infrared. By assuming that a given set of source properties (initial mass, stellar temperature, composition, and evolutionary stage) will provide a typical SED shape and brightness, sources…
On the Nature of the Radio Calibrator and Gamma-Ray Emitting NLS1 Galaxy 3C 286 and Its Multiwavelength Variability
Komossa, S.; Grupe, D.; Kraus, A. +1 more
The quasar 3C 286, a well-known calibrator source in radio astronomy, was found to exhibit exceptional multiwavelength properties. Its rich and complex optical emission-line spectrum revealed its narrow-line Seyfert 1 (NLS1) nature. Given its strong radio emission, this makes 3C 286 one of the radio-loudest NLS1 galaxies known to date. 3C 286 is a…
Development of generic no-scale inflation
Wu, Lina; Shen, Jin-Ke; Li, Tianjun +1 more
We develop generalized no-scale supergravity models of inflation, and then study the corresponding cosmological predictions as well as the formation of primordial black holes (PBHs) and scalar-induced gravitational waves (SIGWs). With a new parameter 0 < a ≤ 1, the generalized no-scale supergravity provides the continuous connections among the …
Thermal and magnetic field structure of near-equatorial coronal holes
Hegde, M.; Hiremath, K. M.
Context. Coronal holes are low-density and unipolar magnetic field structures in the solar corona that trigger geomagnetic disturbances on the Earth. Hence, it is important to understand the genesis and evolutionary behavior of these coronal activity features during their passage across the solar disk.
Aims: We study the day-to-day latitudina…
Solar internetwork magnetic fields: Statistical comparison between observations and MHD simulations
Borrero, J. M.; Ebert, E.; Milić, I.
Context. Although the magnetic fields in the quiet Sun account for the majority of the magnetic energy in the solar photosphere, inferring their exact spatial distribution, origin, and evolution poses an important challenge because the signals lie at the limit of today's instrumental precision. This severely hinders and biases our interpretations,…
Isochrone Fitting of Galactic Globular Clusters—VI. High-latitude Clusters NGC 5024 (M53), NGC 5053, NGC 5272 (M3), NGC 5466, and NGC 7099 (M30)
Savchenko, S. S.; Gontcharov, G. A.; Il'in, V. B. +7 more
We fit various color–magnitude diagrams (CMDs) of the high-latitude Galactic globular clusters NGC 5024 (M53), NGC 5053, NGC 5272 (M3), NGC 5466, and NGC 7099 (M30) by isochrones from the Dartmouth Stellar Evolution Database and Bag of Stellar Tracks and Isochrones for α–enrichment [α/Fe] = +0.4. For the CMDs, we use data sets from Hubble Space Te…
A statistical primer on classical period-finding techniques in astronomy
Shaban, Ahmed; Giertych, Naomi; Haravu, Pragya +1 more
The aim of our paper is to investigate the properties of the classical phase-dispersion minimization (PDM), analysis of variance (AOV), string-length (SL), and Lomb-Scargle (LS) power statistics from a statistician's perspective. We confirm that when the data are perturbations of a constant function, i.e. under the null hypothesis of no period in …
The Dependence of Joy's Law and Mean Tilt as a Function of Flux Emergence Phase
Will, Lucy W.; Norton, Aimee A.; Hoeksema, Jon Todd
Data from the Michelson Doppler Imager (MDI) and Helioseismic and Magnetic Imager (HMI) are analyzed from 1996 to 2023 to investigate tilt angles (γ) of bipolar magnetic regions and Joy's law for Solar Cycles 23 and 24 and a portion of Cycle 25. The HMI radial magnetic field (B r ) and MDI magnetogram (B los) data are used t…