Search Publications
On the Decay of Sunspot Groups and Their Internal Parts in Detail
Muraközy, Judit
The decay of sunspot groups is a relatively unknown field since most studies have focused mainly on the decay of sunspots or sunspot groups, but only on small samples. As an extension of the recent work of Muraközy (2020), which is based on a large verified sample, this study investigates not only the long-term behavior of the decay of sunspot gro…
The Stars of the HETDEX Survey. I. Radial Velocities and Metal-poor Stars from Low-resolution Stellar Spectra
Finkelstein, Steven L.; Casey, Caitlin M.; Schneider, Donald P. +19 more
The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is an unbiased, massively multiplexed spectroscopic survey, designed to measure the expansion history of the universe through low-resolution (R ∼ 750) spectra of Lyα emitters. In its search for these galaxies, HETDEX will also observe a few times 105 stars. In this paper, we pre…
Evidence for Multiple Accretion Events in the Gaia-Sausage/Enceladus Structures
Koo, Jae-Rim; Beers, Timothy C.; Lee, Young Sun +1 more
We present evidence that multiple accretion events are required to explain the origin of the Gaia-Sausage and Enceladus (GSE) structures, based on an analysis of dynamical properties of main-sequence stars from the Sloan Digital Sky Survey Data Release 12 and Gaia Data Release 2. GSE members are selected to have eccentricity (e) > 0.7 and [Fe/H…
The MOSDEF-LRIS Survey: Probing the ISM/CGM Structure of Star-forming Galaxies at z 2 Using Rest-UV Spectroscopy
Siana, Brian; Shapley, Alice E.; Reddy, Naveen A. +6 more
The complex structure of gas, metals, and dust in the interstellar and circumgalactic medium (ISM and CGM, respectively) in star-forming galaxies can be probed by Lyα emission and absorption, low-ionization interstellar (LIS) metal absorption, and dust reddening E(B - V). We present a statistical analysis of the mutual correlations among Lyα equiv…
The Effect of Environment on Star Formation Activity and Morphology at 0.5 < z < 2.5 in CANDELS
Fang, Guanwen; Gu, Yizhou; Yuan, Qirong +2 more
To explore the effect of environment on star formation and the morphological transformation of high-redshift galaxies, we present a robust estimation of localized galaxy overdensity using a density estimator within the Bayesian probability framework. The maps of environmental overdensity at 0.5 < z < 2.5 are constructed for the five CANDELS …
Core Mass Function of a Single Giant Molecular Cloud Complex with 10,000 Cores
Qiu, Keping; Cao, Yue; Zhang, Qizhou +2 more
Similarity in shape between the initial mass function (IMF) and the core mass functions (CMFs) in star-forming regions prompts the idea that the IMF originates from the CMF through a self-similar core-to-star mass mapping process. To accurately determine the shape of the CMF, we create a sample of 8431 cores with the dust continuum maps of the Cyg…
Bursts before Burst: A Comparative Study on FRB 200428-associated and FRB-absent X-Ray Bursts from SGR J1935+2154
Lin, Lin; Zhang, Bing; Dai, Zi-Gao +8 more
Accompanied by an X-ray burst, the fast radio burst (FRB) FRB 200428 was recently confirmed as originating from the Galactic magnetar soft gamma repeater (SGR) SGR J1935+2154. Just before and after FRB 200428 was detected, the Five-hundred-meter Aperture Spherical radio Telescope (FAST) had been monitoring SGR J1935+2154 for eight hours. From UTC …
The Masses of Supernova Remnant Progenitors in NGC 6946
Williams, Benjamin F.; Blair, William P.; Dolphin, Andrew +5 more
We constrained the progenitor masses for 169 supernova remnants (SNRs), eight historically observed supernovae (SNe), and the black hole formation candidate in NGC 6946, finding that they are consistent with originating from a standard initial mass function. Additionally, there were 16 remnants that showed no sign of nearby star formation consiste…
Probing the Hot Circumgalactic Medium with Broad O VI and X-Rays
Nicastro, Fabrizio; Mathur, Smita; Gupta, Anjali +2 more
Most of the baryonic mass in the circumgalactic medium (CGM) of a spiral galaxy is believed to be warm-hot, with temperature around 106 K. The narrow O VI absorption lines probe a somewhat cooler component at $\mathrm{log}\,T({\rm{K}})=5.5$ , but broad O VI absorbers have the potential to probe the hotter CGM. Here we present 376 ks Cha…
Discovery of a Protocluster Core Associated with an Enormous Lya Nebula at z = 2.3
Fan, Xiaohui; Cai, Zheng; Li, Qiong +10 more
The MAMMOTH-1 nebula at z = 2.317 is an enormous Lyα nebula (ELAN) extending to a ~440 kpc scale at the center of the extreme galaxy overdensity BOSS 1441. In this paper, we present observations of the CO(3 - 2) and 250 GHz dust-continuum emission from MAMMOTH-1 using the IRAM NOrthern Extended Millimeter Array. Our observations show that CO(3 - 2…