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Probing the Origin of Changing-look Quasar Transitions with Chandra
Green, Paul J.; Anderson, Scott F.; Bieryla, Allyson +9 more
Extremely variable quasars can also show strong changes in broad-line emission strength and are known as changing-look quasars (CLQs). To study the CLQ transition mechanism, we present a pilot sample of CLQs with X-ray observations in both the bright and faint states. From a sample of quasars with bright-state archival SDSS spectra and (Chandra or…
An R V Map of the Milky Way Revealed by LAMOST
Chen, Bingqiu; Yuan, Haibo; Zhang, Ruoyi
The total-to-selective extinction ratio, R V, is a key parameter for tracing the properties of interstellar dust, as it directly determines the variation of the extinction curve with wavelength. By utilizing accurate color excess measurements from the optical to the mid-infrared range, we have derived R V values for approxima…
The data center for the Spectrometer and Telescope for Imaging X-rays (STIX) on board Solar Orbiter
Massa, Paolo; Krucker, Säm; Piana, Michele +12 more
Context. The Spectrometer and Telescope for Imaging X-rays (STIX) on board Solar Orbiter observes solar X-ray emission in the range of 4-150 keV and produces spectra and images of solar flares over a wide range of flare magnitudes. During nominal operation, STIX continuously generates data. A constant data flow requires fully automated data-proces…
Inferring the presence of very massive stars in local star-forming regions
Schaerer, D.; Martins, F.; Marques-Chaves, R. +1 more
Context. Very massive stars (VMS) have masses in excess of 100 M⊙ and are rare. However, owing to their powerful winds, very high luminosity, and efficient nucleosynthesis, they are key players of star-forming regions. In particular, their strong ionizing fluxes impact the surrounding interstellar medium.
Aims: We aim at detecting …
The JWST PEARLS View of the El Gordo Galaxy Cluster and of the Structure It Magnifies
Grogin, Norman A.; Koekemoer, Anton M.; Pirzkal, Nor +41 more
The massive galaxy cluster El Gordo (z = 0.87) imprints multitudes of gravitationally lensed arcs onto James Webb Space Telescope Near-Infrared Camera (NIRCam) images. Eight bands of NIRCam imaging were obtained in the "Prime Extragalactic Areas for Reionization and Lensing Science" ("PEARLS") program. Point-spread function-matched photometry acro…
Delving deep: A population of extremely dusty dwarfs observed by JWST
Rodighiero, G.; Kartaltepe, J. S.; Dickinson, M. +21 more
Aims: We take advantage of the NIRCam photometric observations available as part of the Cosmic Evolution Early Release Science survey (CEERS) to identify and analyse very red sources in an effort to discover very dusty star forming galaxies.
Methods: We select red galaxies as objects with a S/N > 3 at 4.4 µm and a S/N < 2 in …
Unifying High- and Low-resolution Observations to Constrain the Dayside Atmosphere of KELT-20b/MASCARA-2b
Fu, Guangwei; Brogi, Matteo; Désert, Jean-Michel +10 more
We present high-resolution dayside thermal emission observations of the exoplanet KELT-20b/MASCARA-2b using the MAROON-X spectrograph. Applying the cross-correlation method with both empirical and theoretical masks and a retrieval analysis, we confirm previous detections of Fe I emission lines and we detect Ni I for the first time in the planet (a…
Uncovering the stellar structure of the dusty star-forming galaxy GN20 at z = 4.055 with MIRI/JWST
Ilbert, O.; Nørgaard-Nielsen, H. U.; Östlin, G. +35 more
Luminous infrared galaxies at high redshifts (z > 4) include extreme starbursts that build their stellar mass over short periods of time, that is, of 100 Myr or less. These galaxies are considered to be the progenitors of massive quiescent galaxies at intermediate redshifts (z ∼ 2) but their stellar structure and buildup is unknown. Here, we pr…
2023 Astrophotonics Roadmap: pathways to realizing multi-functional integrated astrophotonic instruments
Monnier, John D.; Anugu, Narsireddy; Kraus, Stefan +77 more
Photonic technologies offer numerous functionalities that can be used to realize astrophotonic instruments. The most spectacular example to date is the ESO Gravity instrument at the Very Large Telescope in Chile that combines the light-gathering power of four 8 m telescopes through a complex photonic interferometer. Fully integrated astrophotonic …
TOI-3235 b: A Transiting Giant Planet around an M4 Dwarf Star
Vanderburg, Andrew; Latham, David W.; Jordán, Andrés +34 more
We present the discovery of TOI-3235 b, a short-period Jupiter orbiting an M dwarf with a stellar mass close to the critical mass at which stars transition from partially to fully convective. TOI-3235 b was first identified as a candidate from TESS photometry and confirmed with radial velocities from ESPRESSO and ground-based photometry from HATSo…