Search Publications
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 …
Age Determination of LAMOST Red Giant Branch Stars Based on the Gradient Boosting Decision Tree Method
Deng, Li-Cai; Chen, Li; Spina, Lorenzo +5 more
In this study, we estimate the stellar ages of LAMOST DR8 red giant branch (RGB) stars based on the gradient boosting decision tree (GBDT) algorithm. We used 2643 RGB stars extracted from the APOKASC-2 asteroseismological catalog as the training data set. After selecting the parameters ([α/Fe], [C/Fe], T eff, [N/Fe], [C/H], log g) highl…
Multiple Emission Lines of Hα Emitters at z ∼ 2.3 from the Broad- and Medium-band Photometry in the ZFOURGE Survey
Momose, Rieko; Kodama, Tadayuki; Nakajima, Kimihiko +8 more
We present a multiple emission line study of ∼1300 Hα emitters (HAEs) at z ∼ 2.3 in the ZFOURGE survey. In contrast to the traditional spectroscopic method, our sample is selected based on the flux excess in the ZFOURGE K s broadband data relative to the best-fit stellar continuum. Using the same method, we also extract the strong dia…
Constraining Stellar Rotation at the Zero-age Main Sequence with TESS
Huang, C. X.; Wright, N. J.; Zhou, G. +5 more
The zero-age main sequence (ZAMS) is a critical phase for stellar angular momentum evolution, as stars transition from contraction-dominated spin-up to magnetic wind-dominated spin-down. We present the first robust observational constraints on rotation for FGK stars at ≈40 Myr. We have analyzed TESS light curves for 1410 members of five young open…
The Disappearance of the Blue and Luminous Progenitor of the Type IIn SN 2010jl
Niu, Zexi; Sun, Ning-Chen; Liu, Jifeng
Type IIn supernovae (SNe) exhibit narrow hydrogen lines that arise from the strong interaction between ejecta and circumstellar material. It remains poorly understood, however, what progenitor stars give rise to these explosions. In this work, we perform a detailed analysis of the progenitor and environment of the nearby Type IIn SN 2010jl. With n…