Search Publications
From Diversity to Dichotomy, and Quenching: Milky-Way-like and Massive Galaxy Progenitors at 0.5 < z <3.0
Patel, Shannon G.; Kajisawa, Masaru; Morishita, Takahiro +4 more
Using the Hubble Space Telescope (HST)/WFC3 and Advanced Camera for Surveys multi-band imaging data taken in CANDELS and 3D-HST, we study the general properties and diversity of the progenitors of the Milky Way (MWs) and local massive galaxy (MGs) at 0.5\lt z\lt 3.0, based on a constant cumulative number density analysis. After careful data reduct…
Mapping the Outer Edge of the Young Stellar Cluster in the Galactic Center
Lu, J. R.; Do, T.; Ghez, A. +3 more
We present new near-infrared spectroscopic observations of the outer edges of the young stellar cluster around the supermassive black hole at the Galactic center. The observations show a break in the surface density profile of young stars at ∼13″ (0.52 pc). These observations spectroscopically confirm previous suggestions of a break based on photo…
The Role of Bars in AGN Fueling in Disk Galaxies Over the Last Seven Billion Years
Santini, Paola; Knapen, Johan H.; Salvato, Mara +3 more
We present empirical constraints on the influence of stellar bars on the fueling of active galactic nuclei (AGNs) out to z = 0.84 using a sample of X-ray-selected AGNs hosted in luminous non-interacting face-on and moderately inclined disk galaxies from the Chandra COSMOS survey. Using high-resolution Hubble Space Telescope imaging to identify bar…
Forward Modeling of Standing Slow Modes in Flaring Coronal Loops
Banerjee, D.; Antolin, P.; Van Doorsselaere, T. +1 more
Standing slow-mode waves in hot flaring loops are exclusively observed in spectrometers and are used to diagnose the magnetic field strength and temperature of the loop structure. Owing to the lack of spatial information, the longitudinal mode cannot be effectively identified. In this study, we simulate standing slow-mode waves in flaring loops an…
The Multi-layer Variable Absorbers in NGC 1365 Revealed by XMM-Newton and NuSTAR
Harrison, F.; Stern, D.; Zhang, W. W. +15 more
Between 2012 July and 2013 February, NuSTAR and XMM-Newton performed four long-look joint observations of the type 1.8 Seyfert, NGC 1365. We have analyzed the variable absorption seen in these observations in order to characterize the geometry of the absorbing material. Two of the observations caught NGC 1365 in an unusually low absorption state, …
Active-region Tilt Angles: Magnetic versus White-light Determinations of Joy's Law
Li, J.; Wang, Y. -M.; Baranyi, T. +1 more
The axes of solar active regions are inclined relative to the east-west direction, with the tilt angle tending to increase with latitude ("Joy's law"). Observational determinations of Joy's law have been based either on white-light images of sunspot groups or on magnetograms, where the latter have the advantage of measuring directly the physically…
Predicting CME Ejecta and Sheath Front Arrival at L1 with a Data-constrained Physical Model
Hess, Phillip; Zhang, Jie
We present a method for predicting the arrival of a coronal mass ejection (CME) flux rope in situ, as well as the sheath of solar wind plasma accumulated ahead of the driver. For faster CMEs, the front of this sheath will be a shock. The method is based upon geometrical separate measurement of the CME ejecta and sheath. These measurements are used…
Multi-wavelength Observations of 3FGL J2039.6-5618: A Candidate Redback Millisecond Pulsar
Greiner, J.; Belfiore, A.; Marelli, M. +8 more
We present multi-wavelength observations of the unassociated γ-ray source 3FGL J2039.6-5618 detected by the Fermi Large Area Telescope. The source γ-ray properties suggest that it is a pulsar, most likely a millisecond pulsar, for which neither radio nor γ-ray pulsations have been detected. We observed 3FGL J2039.6-5618 with XMM-Newton and discove…
Coordinated X-Ray and Optical Observations of Star-Planet Interaction in HD 17156
Scandariato, G.; Pagano, I.; Sozzetti, A. +14 more
The large number of close-in Jupiter-size exoplanets prompts the question whether star-planet interaction (SPI) effects can be detected. We focused our attention on the system HD 17156, having a Jupiter-mass planet in a very eccentric orbit. Here we present results of the XMM-Newton observations and of a five month coordinated optical campaign wit…
Evolution of Star-formation Properties of High-redshift Cluster Galaxies since z = 2
Im, Myungshin; Kim, Jae-Woo; Koekemoer, Anton +4 more
Using a stellar mass-limited sample of ∼46,600 galaxies ({M}*\gt {10}9.1 {M}⊙ ) at 0.5\lt z\lt 2, we show that the stellar mass, rather than the environment, is the main parameter controlling quenching of star formation in galaxies with {M}*\gt {10}10 {M}⊙ out to z = 2. On the othe…