Search Publications
Using AI for Wave-front Estimation with the Rubin Observatory Active Optics System
Thomas, Sandrine; Connolly, Andrew J.; Suberlak, Krzysztof +6 more
The Vera C. Rubin Observatory will, over a period of 10 yr, repeatedly survey the southern sky. To ensure that images generated by Rubin meet the quality requirements for precision science, the observatory will use an active-optics system (AOS) to correct for alignment and mirror surface perturbations introduced by gravity and temperature gradient…
Solar prominence diagnostics and their associated estimated errors from 1D NLTE Mg II h&k modelling
Barczynski, K.; Schmieder, B.; Labrosse, N. +1 more
Aims: We present further development of the rolling root mean square (rRMS) algorithm. These improvements consist of an increase in computational speed and an estimation of the uncertainty on the recovered diagnostics. This improved algorithm is named the cross root mean square (xRMS) algorithm.
Methods: We used the quantile method to re…
Magnetic fields under feedback: a case study of the massive star-forming hub G34.26 + 0.15
Pattle, Kate; Khan, Zacariyya Afzal; Graves, Sarah F.
We present 850
Candidates for Substellar Members of the Orion Nebula Cluster from JWST/NIRCam
Luhman, K. L.
In 2022, the James Webb Space Telescope (JWST) obtained 1–5 µm images of the center of the Orion Nebula Cluster (ONC). I have analyzed these data in an attempt to search for substellar members of the cluster. Using a pair of color–color diagrams, I have identified >200 brown dwarf candidates that lack spectral classifications. Some of the…
Relativistic X-ray reflection from the accreting millisecond X-ray pulsar IGR J17498-2921
Dewangan, Gulab C.; Mondal, Aditya S.; Raychaudhuri, Biplab +3 more
The accreting millisecond X-ray pulsar IGR J17498-2921 went into X-ray outburst on 2023 April 13-15, for the first time since its discovery on 2011 August 11. Here, we report on the first follow-up NuSTAR observation of the source, performed on 2023 April 23, around 10 d after the peak of the outburst. The NuSTAR spectrum of the persistent emissio…
Stellar Variability and Distance Indicators in the Near-infrared in Nearby Galaxies. I. RR Lyrae and Anomalous Cepheids in Draco Dwarf Spheroidal
Marconi, Marcella; Ripepi, Vincenzo; Rejkuba, Marina +4 more
The Draco Dwarf spheroidal (dSph) galaxy is one of the nearest and the most dark-matter-dominated satellites of the Milky Way. We obtained multiepoch near-infrared (NIR, JHK s ) observations of the central region of Draco dSph covering a sky area of ∼21' × 21' using the WIRCam instrument at the 3.6 m Canada–France–Hawaii Telescope. Hom…
Confirming the evolution of the dust mass function in galaxies over the past 5 billion years
Dunne, L.; Maddox, S.; Smith, M. W. L. +3 more
The amount of evolution in the dust content of galaxies over the past 5 billion years of cosmic history is contested in the literature. Here, we present a far-infrared (FIR) census of dust based on a sample of 29 241 galaxies with redshifts ranging from
On the Kinematic Nature of Apparent Disks at High Redshifts: Local Counterparts are Not Dominated by Ordered Rotation but by Tangentially Anisotropic Random Motion
Cappellari, Michele; Gao, Hua; Peng, Yingjie +2 more
It is not straightforward to physically interpret the apparent morphology of galaxies. Recent observations by the James Webb Space Telescope (JWST) revealed a dominant galaxy population at high redshifts (z > 2) that were visually classified as disks for their flattened shapes and/or exponential light profiles. The extensively accepted interpre…
Unveiling the chemical fingerprint of phosphorus-rich stars: II. Heavy-element abundances from UVES/VLT spectra
Masseron, Thomas; García-Hernández, D. A.; Pignatari, Marco +2 more
Context. The atmospheres of phosphorus-rich (P-rich) stars have been shown to contain between 10 and 100 times more P than our Sun. Given its crucial role as an essential element for life, it is especially necessary to uncover the origin of P-rich stars to gain insights into the still unknown nucleosynthetic formation pathways of P in our Galaxy. …
B-Plane Resonant Flybys: Theory Extension to Elliptical Orbits and Dynamic Programming Application
Colombo, Camilla; Campiti, Giulio; Masat, Alessandro
A convenient formalism for the design of resonant flyby trajectories is the B-plane, where postencounter orbits with target resonance conditions or semimajor axes can be analytically mapped. This framework has been developed by many authors starting from the classical Öpik's theory for close encounters, but it still relies on the approximation of …