Search Publications
A Spatially Resolved Survey of Distant Quasar Host Galaxies. II. Photoionization and Kinematics of the ISM
Armus, Lee; Larkin, James E.; Wright, Shelley A. +6 more
We present detailed observations of photoionization conditions and galaxy kinematics in 11 z = 1.39-2.59 radio-loud quasar host galaxies. Data were taken with the OSIRIS integral field spectrograph and the adaptive optics system at the W. M. Keck Observatory that targeted nebular emission lines (Hβ, [O III], Hα, [N II]) redshifted into the near-in…
Years-delayed X-Ray Afterglows of TDEs Originated from Wind-Torus Interactions
Wang, Wei; Shu, Xinwen; Jiang, Ning +8 more
Tidal disruption events (TDEs) occurring in active galactic nuclei (AGNs) are a special class of sources with outstanding scientific significance. TDEs can generate ultrafast winds, which should almost inevitably collide with the preexisting AGN dusty tori. We perform analytical calculations and simulations on the wind-torus interactions and find …
New Families in our Solar Neighborhood: Applying Gaussian Mixture Models for Objective Classification of Structures in the Milky Way and in Simulations
Faucher-Giguère, Claude-André; Sharma, Sanjib; Bonaca, Ana +10 more
The standard picture of galaxy formation motivates the decomposition of the Milky Way into 3-4 stellar populations with distinct kinematic and elemental abundance distributions: the thin disk, thick disk, bulge, and stellar halo. To test this idea, we construct a Gaussian mixture model (GMM) for both simulated and observed stars in the solar neigh…
The Source Locations of Major Flares and CMEs in Emerging Active Regions
Wang, Yuming; Liu, Lijuan; Cui, Jun +1 more
Major flares and coronal mass ejections (CMEs) tend to originate from compact polarity inversion lines (PILs) in solar active regions (ARs). Recently, a scenario named "collisional shearing" was proposed by Chintzoglou et al. to explain the phenomenon, which suggests that the collision between different emerging bipoles is able to form a compact P…
APOGEE-2S Discovery of Light- and Heavy-element Abundance Correlations in the Bulge Globular Cluster NGC 6380
Cunha, Katia; Smith, Verne V.; Majewski, Steven R. +11 more
We derive abundance ratios for nine stars in the relatively high-metallicity bulge globular cluster NGC 6380. We find a mean cluster metallicity between [Fe/H] = -0.80 and -0.73, with no clear evidence for a variation in iron abundances beyond the observational errors. Stars with strongly enhanced [N/Fe] abundance ratios populate the cluster and a…
Mrk 1239: a Type-2 Counterpart of Narrow-line Seyfert-1?
Zhou, Hongyan; Ji, Tuo; Shi, Xiheng +10 more
We present new spectrophotometric and spectropolarimetric observations of Mrk 1239, one of the 8 prototypes that defines type-1 narrow-line Seyfert galaxies (NLS1s). Unlike the other typical NLS1s though, a high degree of polarization (P ∼ 5.6%) and red optical-IR (g-W4 = 12.35) colors suggest that Mrk 1239 is more similar to type-2 act…
Detecting Reconnection Sites Using the Lorentz Transformations for Electromagnetic Fields
Lapenta, Giovanni
We take a pragmatic definition of reconnection to find locations where a reconnection electric field causes an E × B drift that carries two components of the magnetic field toward their elimination. With this in mind as our target, we observe that such locations can be found using a new indicator: the velocity of the Lorentz transformation that el…
Near-infrared Studies of Nova V1674 Herculis: A Shocking Record Breaker
Banerjee, D. P. K.; Starrfield, S.; Page, K. L. +3 more
We present near-infrared spectroscopy of Nova Herculis 2021 (V1674 Her), obtained over the first 70 days of its evolution. This fastest nova on record displays a rich emission line spectrum, including strong coronal line emission with complex structures. The hydrogen line fluxes, combined with a distance of ${4.7}_{-1.0}^{+1.3}$ kpc, give an upper…
14 Her: A Likely Case of Planet-Planet Scattering
Gelino, Christopher R.; Faherty, Jacqueline K.; Bardalez Gagliuffi, Daniella C. +4 more
In this Letter, we measure the full orbital architecture of the two-planet system around the nearby K0 dwarf 14 Herculis. 14 Her (HD 145675, HIP 79248) is a middle-aged ( ${4.6}_{-1.3}^{+3.8}$ Gyr) K0 star with two eccentric giant planets identified in the literature from radial velocity (RV) variability and long-term trends. Using archival RV dat…
Sublimation of Laboratory Ices Millimeter/Submillimeter Experiment (SubLIME): Structure-specific Identifications of Products from UV-photolyzed Methanol Ice
Gerakines, P. A.; Milam, S. N.; Widicus Weaver, S. L. +1 more
Submillimeter/far-IR spectroscopy was used to detect and quantify organic molecules sublimated after the ultraviolet photolysis (at 12 K) and warm-up (up to 300 K) of a methanol (CH3OH) ice sample. Eleven sublimated photoproducts were uniquely identified: carbon monoxide (CO), formaldehyde (H2CO), ketene (C2H2…