Search Publications
A Massive AGB Donor in Scutum X-1: Identification of the First Mira Variable in an X-Ray Binary
Soria, Roberto; Conroy, Charlie; Chakrabarty, Deepto +9 more
The symbiotic X-ray binary Sct X-1 was suggested to be the first known neutron star accreting from a red supergiant companion. Although known for nearly 50 yr, detailed characterization of the donor remains lacking, particularly due to the extremely high reddening toward the source (A V ≳ 25 mag). Here, we present (i) improved localiz…
ALMA Observations of CO Emission from Luminous Lyman-break Galaxies at z = 6.0293-6.2037
Ono, Yoshiaki; Ouchi, Masami; Fujimoto, Seiji +14 more
We present our new Atacama Large Millimeter/submillimeter Array (ALMA) observations targeting CO(6-5) emission from three luminous Lyman-break galaxies (LBGs) at z spec = 6.0293-6.2037 found in the Subaru/Hyper Suprime-Cam survey, whose [O III] 88 µm and [C II] 158 µm emissions have been detected with ALMA. We find a margina…
Explanation of Heliospheric Energetic Neutral Atom Fluxes Observed by the Interstellar Boundary Explorer
McComas, D. J.; Rankin, J. S.; Dayeh, M. A. +3 more
Interstellar neutral atoms propagating into the heliosphere experience charge exchange with the supersonic solar wind (SW) plasma, generating ions that are picked up by the SW. These pickup ions (PUIs) constitute ~25% of the proton number density by the time they reach the heliospheric termination shock (HTS). Preferential acceleration of PUIs at …
Variations of the Internal Asymmetries of Sunspot Groups during Their Decay
Muraközy, Judit
The aim of the present study is to show the varying asymmetries during the decay of sunspot groups. The source of input data is the SOHO/MDI-Debrecen Database sunspot catalog that contains the magnetic polarity data for time interval 1996-2010. Several types of asymmetries were examined on the selected sample of 142 sunspot groups. The leading-fol…
No Evolution in the Half-mass Radius of Milky Way-type Galaxies over the Last 10 Gyr
Tacchella, Sandro; Park, Minjung; Naidu, Rohan P. +3 more
The Milky Way (MW) galaxy is in focus, thanks to new observational data. Here we shed new light on the MW's past by studying the structural evolution of MW progenitors, which we identify from extragalactic surveys. Specifically, we constrain the stellar-mass growth history (SMGH) of the MW with two methods: (i) direct measurement of the MW's star …
Ages of Main-sequence Turnoff Stars from the GALAH Survey
Wu, Yaqian; Chen, Yuqin; Bi, Shaolan +6 more
Main-sequence turnoff (MSTO) stars are good tracers of Galactic populations since their ages can be reliably estimated from atmospheric parameters. Based on the GALAH survey, we use the Yale rotation evolution code to determine the ages of 2926 MSTO stars with a mean age uncertainty of ~10% considering the variation of C and O abundances. The ages…
Eruption of the EUV Hot Channel from the Solar Limb and Associated Moving Type IV Radio Burst
Zhang, J.; Démoulin, P.; Gopalswamy, N. +3 more
Using the observations from the Solar Dynamics Observatory, we study an eruption of a hot-channel flux rope (FR) near the solar limb on 2015 February 9. The pre-eruptive structure is visible mainly in EUV 131 Å images, with two highly sheared loop structures. They undergo a slow rising motion and then reconnect to form an eruptive hot channel, as …
Vibrationally Excited Lines of HC3N Associated with the Molecular Disk around the G24.78+0.08 A1 Hypercompact H II Region
Nakamura, Fumitaka; Takakuwa, Shigehisa; Taniguchi, Kotomi +7 more
We have analyzed Atacama Large Millimeter/submillimeter Array Band 6 data of the hypercompact H II region G24.78+0.08 A1 (G24 HC H II) and report the detection of vibrationally excited lines of HC3N (v 7 = 2, J = 24 - 23). The spatial distribution and kinematics of a vibrationally excited line of HC3N (v 7
Dense Gas and Star Formation in Nearby Infrared-bright Galaxies: APEX Survey of HCN and HCO+ J = 2 → 1
Wang, Junzhi; Gao, Yu; Zhang, Zhi-Yu +6 more
Both Galactic and extragalactic studies of star formation suggest that stars form directly from dense molecular gas. To trace such high volume density gas, HCN and HCO+ J = 1 → 0 have been widely used for their high dipole moments, relatively high abundances, and often being the strongest lines after CO. However, HCN and HCO+…
Surveying the Giant H II Regions of the Milky Way with SOFIA. IV. Sgr D, W42, and a Reassessment of the Giant H II Region Census
Lim, Wanggi; Karnath, Nicole; De Buizer, James M. +2 more
This is the fourth paper exploring the infrared properties of giant H II regions with the FORCAST instrument on the Stratospheric Observatory For Infrared Astronomy (SOFIA). Our survey utilizes the census of 56 Milky Way giant H II regions identified by Conti & Crowther, and in this paper we present the 20 and 37 µm imaging data we obtai…