Search Publications
An XMM-Newton study of six narrow-line Seyfert 1 galaxies at z = 0.35-0.92
Fabian, Andrew C.; Brandt, William N.; Reynolds, Christopher S. +5 more
We report a detailed analysis of the XMM-Newton spectra of six narrow-line Seyfert 1 (NLS1) galaxies at redshift z = 0.35-0.92. Compared with the NLS1s at lower redshift in the previously most-studied sample, these NLS1s have larger black hole (BH) masses ($\log \, M_\mathrm{BH}\gt 7.5$ ) with similar or even lower Eddington ratios. Our extended X…
The multiplicity of massive stars in the Scorpius OB1 association through high-contrast imaging
Pauwels, T.; Sana, H.; Reggiani, M. +2 more
Context. Despite past efforts, a comprehensive theory of massive star formation is still lacking. One of the most remarkable properties of massive stars is that almost all of them are found in binaries or higher-order multiple systems. Since multiplicity is an important outcome parameter of a star formation process, observations that cover the ful…
Retrospective Search for Strongly Lensed Supernovae in the DESI Legacy Imaging Surveys
Schlegel, David J.; Huang, Xiaosheng; Suzuki, Nao +3 more
The introduction of deep wide-field surveys in recent years and the adoption of machine-learning techniques have led to the discoveries of ${ \mathcal O }({10}^{4})$ strong gravitational lensing systems and candidates. However, the discovery of multiply-lensed transients remains a rarity. Lensed transients and especially lensed supernovae are inva…
Gas kinematics around filamentary structures in the Orion B cloud
Peretto, Nicolas; Hughes, Annie; Kainulainen, Jouni +27 more
Context. Understanding the initial properties of star-forming material and how they affect the star formation process is key. From an observational point of view, the feedback from young high-mass stars on future star formation properties is still poorly constrained.
Aims: In the framework of the IRAM 30m ORION-B large program, we obtained ob…
Deciphering Solar Coronal Heating: Energizing Small-scale Loops through Surface Convection
Madjarska, M. S.; Rouppe van der Voort, L.; Joshi, R. +4 more
The solar atmosphere is filled with clusters of hot small-scale loops commonly known as coronal bright points (CBPs). These ubiquitous structures stand out in the Sun by their strong X-ray and/or extreme-ultraviolet (EUV) emission for hours to days, which makes them a crucial piece when solving the solar coronal heating puzzle. In addition, they c…
Analysis of Charon's spectrum at 2.21- µm from New Horizons/LEISA and Earth-based observations
Singer, Kelsi N.; Stern, S. Alan; Weaver, Harold A. +9 more
We examine the 2.21- µm band from 19 disk-integrated Charon spectra measured by New Horizons/LEISA in the week leading up to its closest encounter with the Pluto system. These observations cover one Charon rotation period. Additionally, we analyze Charon's 2.21- µm band from 22 Earth-based spectra obtained over the last two decades. We…
Pulse frequency fluctuations of persistent accretion powered pulsars
Serim, M. M.; Baykal, A.; Serim, D.
In this study, we examine the long-term torque noise fluctuations of persistent X-ray binaries Her X-1, Vela X-1, GX 301-2, Cen X-3, 4U 1538-53, OAO 1657-415, and 4U 1626-67 using the historical pulse frequency measurements provided by CGRO/BATSE and Fermi/GBM. We find that known disc-fed sources exhibit a 1/ω2 red noise component in th…
Three low-mass companions around aged stars discovered by TESS
Hellier, Coel; Bieryla, Allyson; Latham, David W. +42 more
We report the discovery of three transiting low-mass companions to aged stars: a brown dwarf (TOI-2336b) and two objects near the hydrogen burning mass limit (TOI-1608b and TOI-2521b). These three systems were first identified using data from the Transiting Exoplanet Survey Satellite (TESS). TOI-2336b has a radius of 1.05 ± 0.04 RJ, a m…
The HH 24 Complex: Jets, Multiple Star Formation, and Orphaned Protostars
Yen, Hsi-Wei; Comerón, F.; Bally, J. +9 more
The HH 24 complex harbors five collimated jets emanating from a small protostellar multiple system. We have carried out a multiwavelength study of the jets, their driving sources, and the cloud core hosting the embedded stellar system, based on data from the Hubble Space Telescope, Gemini, Subaru, Apache Point Observatory 3.5 m, Karl G. Jansky Ver…
Metal Content in Relativistically Jetted and Radio-Quiet Quasars in the Main Sequence Context
Panda, Swayamtrupta; Marziani, Paola; Deconto Machado, Alice +1 more
The optical and UV properties of radio-quiet (RQ) and radio-loud (RL, relativistically "jetted") active galactic nuclei (AGN) are known to differ markedly; however, it is still unclear what is due to a sample selection and what is associated with intrinsic differences in the inner workings of their emitting regions. Chemical composition is an impo…