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Sp1149. II. Spectroscopy of H II Regions near the Critical Curve of MACS J1149 and Cluster Lens Models
Filippenko, Alexei V.; Oguri, Masamune; Diego, Jose M. +3 more
Galaxy-cluster gravitational lenses enable the study of faint galaxies even at large lookback times, and, recently, time-delay constraints on the Hubble constant. There have been few tests, however, of lens model predictions adjacent to the critical curve (≲8″) where the magnification is greatest. In a companion paper, we use the GLAFIC lens model…
Chandra/HETG Doppler velocity measurements in stellar coronal sources
de Plaa, J.; Costantini, E.; Paltani, S. +4 more
Stellar coronal sources have been observed in the past not only for their astrophysical interest in the field of binary system evolution and interaction but also for their invaluable roles as benchmarks for plasma spectral models and as calibration sources for high resolution spectroscopic X-ray instruments. These include the gratings on-board Cha…
Rotation in stellar evolution: Probing the influence on population synthesis in high-redshift galaxies
Sun, Weijia
Stellar population synthesis (SPS) is essential for understanding galaxy formation and evolution. However, the recent discovery of rotation-driven phenomena in star clusters warrants a review of uncertainties in SPS models caused by overlooked factors, including stellar rotation. In this study, we investigated the impact of rotation on SPS specifi…
Recurrently Propagating Intensity Disturbances along Polar Plumes Observed in White Light and Extreme Ultraviolet
Moon, Yong-Jae; Lee, Harim; Cho, Kyung-Suk +5 more
We study properties of intensity disturbances along polar coronal rays that are associated with plumes below. For this, we draw azimuth–time images of extreme ultraviolet (EUV) emission of 171 Å band observed by the SDO/AIA and white light (WL) observed by the SOHO/LASCO C2 in 2020 July. From the azimuth–time image, we define two tracks in which t…
New Yarkovsky drift detections using astrometric observations of NEAs
Lisa, Bedini; Giacomo, Tommei
The Yarkovsky drift represents the semi-major axis variation of a celestial body due to the Yarkovsky effect. This thermodynamic effect acts more significantly on bodies with a diameter between ≈10 m and ≈30 km . Therefore, the orbits of many minor bodies of the solar system are affected: knowing the value of the Yarkovsky drift can be crucial to …
Searching for Neutral Hydrogen Escape from the 120 Myr Old Sub-Neptune HIP94235b using HST
Mayorga, L. C.; Zhou, George; Wittenmyer, Robert A. +9 more
HIP94235 b, a 120 Myr old sub-Neptune, provides us the unique opportunity to study mass loss at a pivotal stage of the system's evolution: the end of a 100 Myr old phase of intense XUV irradiation. We present two observations of HIP94235 b using the Hubble Space Telescope's Space Telescope Imaging Spectrograph in the Lyα wavelength region. We do n…
Optimal Fitting and Debiasing for Detectors Read Out Up-the-Ramp
Brandt, Timothy D.
This paper derives the optimal fit to a pixel's count rate in the case of an ideal detector read out nondestructively in the presence of both read and photon noise. The approach is general for any readout scheme, provides closed-form expressions for all quantities, and has a computational cost that is linear in the number of resultants (groups of …
Two stellar populations with different metallicities in the low-mass globular cluster Gran 5
Chung, Chul; Lee, Young-Wook; Koch-Hansen, Andreas J. +3 more
Context. With the increasing number of discoveries of globular clusters in the inner Milky Way, the need for spectroscopic confirmation and further investigation of their stellar populations and chemodynamical properties has become crucial. Aims. Gran 5 is a newly reported low-mass globular cluster located close to the Galactic center, and it is t…
BSN: The First Light Curve Analysis of the Total Eclipse Binary System EL Tuc
Poro, Atila; Sarvari, Elham; Fernández Lajús, Eduardo
We conducted the first light curve study of the binary star EL Tuc within the Binary Systems of South and North project's framework. The photometric observations were made using standard multiband BVR c I c filters at an observatory in Argentina. We presented a new ephemeris for EL Tuc and a linear fit to the O – C diagra…
Observations of the Ultraviolet-bright Star ZNG 1 in the Globular Cluster M5 (NGC 5904)
Dixon, William V.
We have analyzed archival spectra of the hot UV-bright star ZNG 1 in the globular cluster M5 (NGC 5904) obtained with the Far Ultraviolet Spectroscopic Explorer and the Space Telescope Imaging Spectrograph. From these data, we derive an effective temperature T eff = 43,000 ± 1400 K, a surface gravity $\mathrm{log}g$ = 4.47 ± 0.08, a rot…