Search Publications
Inferring Binary and Trinary Stellar Populations in Photometric and Astrometric Surveys
Leistedt, Boris; Hogg, David W.; Widmark, Axel
Multiple stellar systems are ubiquitous in the Milky Way but are often unresolved and seen as single objects in spectroscopic, photometric, and astrometric surveys. However, modeling them is essential for developing a full understanding of large surveys such as Gaia and connecting them to stellar and Galactic models. In this paper, we address this…
Reverse Current Model for Coronal Mass Ejection Cavity Formation
Li, Hui; Haw, Magnus A.; Wongwaitayakornkul, Pakorn +1 more
We report here a new model for explaining the three-part structure of coronal mass ejections (CMEs). The model proposes that the cavity in a CME forms because a rising electric current in the core prominence induces an oppositely directed electric current in the background plasma; this eddy current is required to satisfy the frozen-in magnetic flu…
Tidal Interactions and Mergers in Intermediate-redshift EDisCS Clusters
Moustakas, John; Aragón-Salamanca, Alfonso; Lotz, Jennifer M. +6 more
We study the fraction of tidal interactions and mergers (TIMs) with well-identified observability timescales (f TIM) in group, cluster, and accompanying field galaxies and its dependence on redshift (z), cluster velocity dispersion (σ), and environment analyzing Hubble Space Telescope/ACS images and catalogs from the ESO Distant Cluster…
Variability-selected Low-luminosity Active Galactic Nuclei Candidates in the 7 Ms Chandra Deep Field-South
Lehmer, B. D.; Brandt, W. N.; Vignali, C. +13 more
In deep X-ray surveys, active galactic nuclei (AGNs) with a broad range of luminosities have been identified. However, cosmologically distant low-luminosity AGN (LLAGN, {L}{{X}}≲ {10}42 erg s-1) identification still poses a challenge because of significant contamination from host galaxies. Based on the 7 Ms Chandra…
The Mass and Absorption Column Densities of Galactic Gaseous Halos. II. The High Ionization State Ions
Bregman, Joel N.; Qu, Zhijie
The high ionization state ions trace the hot gases in the universe, of which gaseous halos around galaxies are a major contributor. Following Qu & Bregman, we calculate the gaseous halo contribution to the observed column density distributions for these ions by convolving the gaseous halo model with the observed stellar mass function. The pred…
Reconstruction of the Dark Energy Equation of State from the Latest Observations
Xia, Jun-Qing; Yang, Yang; Dai, Ji-Ping
Since the discovery of the accelerating expansion of our universe in 1998, studying the features of dark energy has remained a hot topic in modern cosmology. In the literature, dark energy is usually described by w ≡ P/ρ, where P and ρ denote its pressure and energy density. Therefore, exploring the evolution of w is the key approach to understand…
On the Full-range β Dependence of Ion-scale Spectral Break in the Solar Wind Turbulence
He, Jiansen; Wang, Xin; Wang, Linghua +1 more
The power spectrum of magnetic fluctuations has a break at the high-frequency end of the inertial range. Beyond this break, the spectrum becomes steeper than the Kolmogorov law f -5/3. The break frequency was found to be associated with plasma beta (β). However, the full-range β dependence of the ion-scale spectral break has not been pr…
A Radio Frequency Study of the Accreting Millisecond X-ray Pulsar, IGR J16597-3704, in the Globular Cluster NGC 6256
Maccarone, T. J.; Altamirano, D.; Degenaar, N. +14 more
We present Karl G. Jansky Very Large Array radio frequency observations of the new accreting millisecond X-ray pulsar (AMXP), IGR J16597-3704, located in the globular cluster NGC 6256. With these data, we detect a radio counterpart to IGR J16597-3704, and determine an improved source position. Pairing our radio observations with quasi-simultaneous…
High-resolution SOFIA/EXES Spectroscopy of SO2 Gas in the Massive Young Stellar Object MonR2 IRS3: Implications for the Sulfur Budget
Montiel, Edward; Neufeld, David A.; Blake, Geoffrey A. +10 more
Sulfur has been observed to be severely depleted in dense clouds leading to uncertainty in the molecules that contain it and the chemistry behind their evolution. Here, we aim to shed light on the sulfur chemistry in young stellar objects (YSOs) by using high-resolution infrared spectroscopy of absorption by the ν 3 rovibrational band o…
Independent Estimation of Black Hole Mass for the γ-ray-detected Archetypal Narrow-line Seyfert 1 Galaxy 1H 0323+342 from X-Ray Variability
Komossa, S.; Jin, Chichuan; Yuan, Weimin +2 more
γ-ray-detected narrow-line Seyfert 1 galaxies (NLS1s) are a newly discovered class of radio-loud active galactic nuclei (AGNs) that launch powerful jets that are generally found only in blazars and radio galaxies. However, their black hole (BH) masses as estimated from their broad emission lines are an order of magnitude or more lower than those i…