Search Publications
Deep Chandra Observation of the Remarkable Ionization Cones of NGC 5252
Elvis, Martin; Guainazzi, Matteo; Bianchi, Stefano +4 more
Seyfert galaxy NGC 5252 harbors enormously extended ionization cones that have been previously detected in the optical and X-ray band, offering a unique opportunity to investigate the interaction between the central active galactic nucleus (AGN) and the surrounding gas in the AGN host galaxy. We present deep Chandra imaging spectroscopy of NGC 525…
HST astrometry of the closest brown dwarfs-II. Improved parameters and constraints on a third body
Apai, D.; Pourbaix, D.; Bedin, L. R. +5 more
Located at less than two pc away, Luhman 16 AB (WISE J104915.57-531906.1) is the closest pair of brown dwarfs and the third closest "stellar" system to Earth. An exoplanet candidate in the Luhman 16 binary system was reported in 2017 based on a weak astrometric signature in the analysis of 12 HST epochs. An additional epoch collected in 2018 and r…
Peering above the clouds of the warm Neptune GJ 436 b with CRIRES+
Gandhi, Siddharth; Snellen, Ignas A. G.; Grasser, Natalie +2 more
Context. Exoplanets with masses between Earth and Neptune are amongst the most commonly observed, yet their properties are poorly constrained. Their transmission spectra are often featureless, which indicate either high-altitude clouds or a high atmospheric metallicity. The archetypical warm Neptune GJ 436 b is such a planet showing a flat transmi…
HdC and EHe stars through the prism of Gaia DR3. Evolution of RV amplitude and dust formation rate with effective temperature
Tisserand, P.; Crawford, C. L.; Clayton, G. C. +3 more
Context. The Gaia DR3 release includes heliocentric radial velocity measurements and velocity variability indices for tens of millions of stars observed over 34 months.
Aims: In this study, we utilise these indices to investigate the intrinsic radial velocity variations of Hydrogen-deficient Carbon (HdC) stars and Extreme Helium (EHe) stars a…
JWST-FEAST: Feedback in Emerging extrAgalactic Star clusTers: Calibration of Star Formation Rates in the Mid-infrared with NGC 628
Östlin, Göran; Smith, Linda J.; Melinder, Jens +19 more
New JWST near-infrared imaging of the nearby galaxy NGC 628 from the JWST Cycle 1 program Feedback in Emerging extrAgalactic Star clusTers (JWST-FEAST) is combined with archival JWST mid-infrared imaging to calibrate the 21 µm emission as a star formation rate (SFR) indicator at ∼120 pc scales. The Paα (1.8756 µm) hydrogen recombinatio…
Comparing emission- and absorption-based gas-phase metallicities in GRB host galaxies at z = 2-4 using JWST
Tagliaferri, G.; Salvaterra, R.; D'Elia, V. +34 more
Much of what is known of the chemical composition of the universe is based on emission line spectra from star-forming galaxies. Emission-based inferences are, nevertheless, model-dependent and they are dominated by light from luminous star-forming regions. An alternative and sensitive probe of the metallicity of galaxies is through absorption line…
X-Ray Characterization of the Pulsar PSR J1849-0001 and Its Wind Nebula G32.64+0.53 Associated with TeV Sources Detected by H.E.S.S., HAWC, Tibet ASγ, and LHAASO
Woo, Jooyun; An, Hongjun; Mori, Kaya +6 more
We report on the X-ray emission properties of the pulsar PSR J1849-0001 and its wind nebula (PWN), as measured by Chandra, XMM-Newton, NICER, Swift, and NuSTAR. In the X-ray data, we detected the 38 ms pulsations of the pulsar up to ~60 keV with high significance. Additionally, we found that the pulsar's on-pulse spectral energy distribution displ…
Quantifying the Transit Light Source Effect: Measurements of Spot Temperature and Coverage on the Photosphere of AU Microscopii with High-resolution Spectroscopy and Multicolor Photometry
Wakeford, Hannah R.; Mann, Andrew W.; Plavchan, Peter +5 more
AU Microscopii (AU Mic) is an active 24 ± 3 Myr pre-main-sequence M dwarf in the stellar neighborhood (d = 9.7 pc) with a rotation period of 4.86 days. The two transiting planets orbiting AU Mic, AU Mic b and c, are warm sub-Neptunes on 8.5 and 18.9 day periods and are targets of interest for atmospheric observations of young planets. Here we stud…
Discovery of a one-sided radio filament of PSR J0538+2817 in S147: escape of relativistic PWN leptons into surrounding supernova remnant?
Churazov, E. M.; Khabibullin, I. I.; Bykov, A. M. +2 more
We report the discovery of a faint radio filament near PSR J0538+2817 in the NVSS, CGPS, and the Rapid ASKAP Continuum Survey data. This pulsar is plausibly associated with the supernova that gave rise to the Spaghetti nebula (Simeis 147). The structure is one-sided and appears to be almost aligned (within 17 degrees) with the direction of the pul…
Heterogeneous outgassing regions identified on active centaur 29P/Schwassmann–Wachmann 1
Schambeau, Charles A.; Villanueva, Geronimo L.; Faggi, Sara +11 more
Centaurs are transitional objects between primitive trans-Neptunian objects and Jupiter-family comets. Their compositions and activities provide fundamental clues regarding the processes affecting the evolution of and interplay between these small bodies. Here we report observations of centaur 29P/Schwassmann–Wachmann 1 (29P) with the James Webb S…