Search Publications
X-ray timing and spectral variability properties of blazars S5 0716 + 714, OJ 287, Mrk 501, and RBS 2070
Mohorian, Maksym; Bhatta, Gopal; Adhikari, Tek P. +6 more
The X-ray emission from blazars has been widely investigated using several space telescopes. In this work, we explored statistical properties of the X-ray variability in the blazars S5 0716+714, OJ 287, Mkn 501, and RBS 2070 using the archival observations from the XMM-Newton telescope between the period 2002-2020. Several methods of timing and sp…
A Gaia View on the Star Formation in the Monoceros OB1 and R1 Associations
Lim, Beomdu; Lee, Jeong-Eun; Park, Byeong-Gon +5 more
Stellar kinematics provides the key to understanding the star formation process. In this respect, we present a kinematic study of the Monoceros OB1 (Mon OB1) and R1 (Mon R1) associations using the recent Gaia data and radial velocities of stars derived from high-resolution spectroscopy and the literature. A total of 728 members are selected using …
A Partial Filament Eruption in Three Steps Induced by External Magnetic Reconnection
Xu, Zhe; Li, Leping; Zhang, Qingmin +6 more
We present an investigation of partial filament eruption on 2012 June 17 in the active region NOAA 11504. For the first time, we observed the vertical splitting process during the partial eruption with high-resolution narrowband images at 10830 Å. The active filament was rooted in a small δ-sunspot of the active region. Particularly, it underwent …
The Lyman Alpha Reference Sample. XII. Morphology of extended Lyman alpha emission in star-forming galaxies
Östlin, G.; Hayes, M.; Kunth, D. +7 more
Aims: We use Hubble Space Telescope data of 45 nearby star-forming galaxies to investigate properties of Lyman-alpha (Lyα) halos, Lyα morphology, and the star-forming characteristics of galaxies. We study how the morphology of Lyα emission is related to other Lyα observables. Furthermore, we study the interdependencies of Lyα morphological qu…
The Influence of 10 Unique Chemical Elements in Shaping the Distribution of Kepler Planets
Cunha, Katia; Smith, Verne V.; Mahadevan, Suvrath +15 more
The chemical abundances of planet-hosting stars offer a glimpse into the composition of planet-forming environments. To further understand this connection, we make the first ever measurement of the correlation between planet occurrence and chemical abundances for ten different elements (C, Mg, Al, Si, S, K, Ca, Mn, Fe, and Ni). Leveraging data fro…
MARS: A New Maximum-entropy-regularized Strong Lensing Mass Reconstruction Method
Jee, M. James; Cha, Sangjun
Free-form strong-lensing (SL) mass reconstructions typically suffer from overfitting, which manifests itself as false-positive small-scale fluctuations. We present a new free-form MAximum-entropy ReconStruction (MARS) method without the assumption that light traces mass (LTM). The MARS algorithm enables us to achieve excellent convergence in sourc…
The Nascent Milliquasar VT J154843.06+220812.6: Tidal Disruption Event or Extreme Accretion State Change?
Hallinan, Gregg; Graham, Matthew; Lu, Wenbin +5 more
We present a detailed multiwavelength follow-up of the nuclear radio flare VT J154843.06+220812.6, hereafter VT J1548. VT J1548 was selected as a ~1 mJy radio flare in 3 GHz observations from the Very Large Array Sky Survey. It is located in the nucleus of a low-mass ( $\mathrm{log}{M}_{\mathrm{BH}}/{M}_{\odot }\sim 6$ ) host galaxy with weak or n…
Timing and spectral analysis of 2S 1417-624 during its 2018 outburst
Serim, M. M.; Şahiner, Ş.; Baykal, A. +4 more
We investigate timing and spectral characteristics of the transient X-ray pulsar 2S 1417-624 during its 2018 outburst with NICER follow up observations. We describe the spectra with high-energy cut-off and partial covering fraction absorption (PCFA) model and present flux-dependent spectral changes of the source during the 2018 outburst. Utilizing…
Sizing from the smallest scales: the mass of the Milky Way
Cooper, M. C.; Simon, J. D.; Ji, A. P. +6 more
As the Milky Way and its satellite system become more entrenched in near field cosmology efforts, the need for an accurate mass estimate of the Milky Way's dark matter halo is increasingly critical. With the second and early third data releases of stellar proper motions from Gaia, several groups calculated full 6D phase-space information for the p…
A Panchromatic Study of Massive Stars in the Extremely Metal-poor Local Group Dwarf Galaxy Leo A
McQuinn, Kristen B. W.; Williams, Benjamin F.; Choi, Yumi +17 more
We characterize massive stars (M > 8 M ⊙) in the nearby (D ∼ 0.8 Mpc) extremely metal-poor (Z ∼ 5% Z ⊙) galaxy Leo A using Hubble Space Telescope ultraviolet (UV), optical, and near-infrared (NIR) imaging along with Keck/Low-Resolution Imaging Spectrograph and MMT/Binospec optical spectroscopy for 18 main-sequence OB stars…