Search Publications
Discovery of the Longest-period Classical Cepheid in the Milky Way
Soszyński, I.; Udalski, A.; Szymański, M. K. +12 more
We report the discovery of the classical Cepheid OGLE-GD-CEP-1884 (= GDS_J1535467-555656) with the longest pulsation period known in our Galaxy. The period of 78.14 days is nearly 10 days longer than that of the previous record-holding Cepheid, S Vulpeculae, and thus, OGLE-GD-CEP-1884 can be categorized as the first ultra-long-period Cepheid in th…
Magnetic Fields in M-dwarf Members of the Pleiades Open Cluster Using APOGEE Spectra
Wanderley, Fábio; Cunha, Katia; Smith, Verne V. +10 more
Average magnetic field measurements are presented for 62 M-dwarf members of the Pleiades open cluster, derived from Zeeman-enhanced Fe I lines in the H band. A Markov Chain Monte Carlo methodology was employed to model magnetic filling factors using Sloan Digital Sky Survey (SDSS) IV APOGEE high-resolution spectra, along with the radiative transfe…
Dark Photon Dark Matter and Low-frequency Gravitational-wave Detection with Gaia-like Astrometry
Wang, Xin; Zhao, Yue; An, Haipeng +3 more
Astrometric surveys offer us a method for searching for elusive cosmic signatures, such as ultralight dark photon dark matter and gravitational waves (GWs), by observing the temporal change of stars' apparent locations. The detection capabilities of such surveys rapidly decrease at low frequencies, because the signals become hardly distinguishable…
Blowing Star Formation Away in Active Galactic Nuclei Hosts. I. Observation of Warm Molecular Outflows with JWST MIRI
Riffel, Rogério; Zakamska, Nadia L.; Storchi-Bergmann, Thaisa +4 more
We use the James Webb Space Telescope Mid-Infrared Instrument medium-resolution spectrometer observations of the radio-loud active galactic nucleus (AGN) host UGC 8782 to map the warm molecular and ionized gas kinematics. The data reveal spatially resolved outflows in the inner 2 kpc, seen in low ionization (traced by the [Ar II] 6.99 µm emi…
Observation of a Fully-formed Forward–Reverse Shock Pair due to the Interaction between Two Coronal Mass Ejections at 0.5 au
Lugaz, Noé; Wimmer-Schweingruber, Robert F.; Dresing, Nina +17 more
We report direct observations of a fast magnetosonic forward–reverse shock pair observed by Solar Orbiter on 2022 March 8 at the short heliocentric distance of 0.5 au. The structure, sharing some features with fully-formed stream interaction regions, is due to the interaction between two successive coronal mass ejections (CMEs), never previously o…
The First Combined Hα and Rest-UV Spectroscopic Probe of Galactic Outflows at High Redshift
Tacconi, L. J.; Shapley, Alice E.; Reddy, Naveen A. +6 more
We investigate the multiphase structure of gas flows in galaxies. We study 80 galaxies during the epoch of peak star formation (1.4 ≤ z ≤ 2.7) using data from the Keck/Low-Resolution Imaging Spectrometer (LRIS) and the Very Large Telescope/K-Band Multi-Object Spectrograph (KMOS). Our analysis provides a simultaneous probe of outflows using UV emis…
Evidence of Continuous Reconnection along a Helmet Streamer Current Sheet Observed by WISPR on Parker Solar Probe
Vourlidas, Angelos; Qiu, Jiong; Stenborg, Guillermo +5 more
Parker Solar Probe's second solar encounter from 2019 March 30 to April 11 occurred during a period when the corona had a simple magnetic structure and relatively flat heliospheric current sheet (HCS), which was in the field of view of the Wide-field Imager for Solar Probe (WISPR) throughout. The images show an almost continual flow of transient d…
The Truncated Circumgalactic Medium of the Large Magellanic Cloud
Fox, Andrew J.; Lehner, Nicolas; Tumlinson, Jason +6 more
The Large Magellanic Cloud (LMC) is the nearest massive galaxy to the Milky Way (MW). Its circumgalactic medium (CGM) is complex and multiphase, containing both stripped H I structures like the Magellanic Stream and Bridge and a diffuse warm corona seen in high-ion absorption. We analyze 28 active galactic nucleus sight lines passing within 35 kpc…
Active Galactic Nucleus Properties of ∼1 Million Member Galaxies of Galaxy Groups and Clusters at z < 1.4 Based on the Subaru Hyper Suprime-Cam Survey
Goto, Tomotsugu; Imanishi, Masatoshi; Schramm, Malte +17 more
Herein, we present the statistical properties of active galactic nuclei (AGNs) for approximately 1 million member galaxies of galaxy groups and clusters with 0.1 < cluster redshift (z cl) < 1.4 selected using the Subaru Hyper Suprime-Cam, the so-called CAMIRA clusters. In this research, we focused on the AGN power fraction (f
On the Properties of X-Ray Corona in Seyfert 1 Galaxies
Stalin, C. S.; Ricci, Claudio; Marchesi, S. +4 more
We carried out a uniform and systematic analysis of a sample of 112 nearby bright Seyfert 1 type active galactic nuclei, the observations of which were carried out by the Nuclear Spectroscopic Telescope Array between 2013 August and 2022 May. The main goal of this analysis is to investigate the nature of the X-ray corona in Seyfert 1 galaxies. By …