Search Publications
Black Hole Spin Measurements in LMC X-1 and Cyg X-1 Are Highly Model Dependent
Zdziarski, Andrzej A.; Szanecki, Michał; Dewangan, Gulab +4 more
The black hole spin parameter, a *, was measured to be close to its maximum value of 1 in many accreting X-ray binaries. In particular, a * ≳ 0.9 was found in a number of studies of LMC X-1. These measurements were claimed to take into account both statistical and systematic uncertainties. We perform new measurements using a …
To be, or not to be: Balmer breaks in high-z galaxies with JWST
Coe, Dan; Bradley, Larry D.; Zackrisson, Erik +7 more
Standard models of structure formation allow us to predict the cosmic timescales relevant for the onset of star formation and the assembly history of galaxies at high redshifts (z > 10). The strength of the Balmer break represents a well-known diagnostic of the age and star formation history of galaxies, which enables us to compare observations…
A Comprehensive Correction of the Gaia DR3 XP Spectra
Xiang, Maosheng; Huang, Yang; Niu, Zexi +7 more
By combining spectra from the CALSPEC and NGSL, as well as spectroscopic data from the LAMOST Data Release 7 (DR7), we have analyzed and corrected the systematic errors of the Gaia DR3 BP/RP (XP) spectra. The errors depend on the normalized spectral energy distribution (simplified by two independent "colors") and G magnitude. Our corrections are a…
2D disc modelling of the JWST line spectrum of EX Lupi
Woitke, P.; Kamp, I.; Ábrahám, P. +3 more
We introduce a number of improvements to the thermo-chemical disc modelling code PRODIMO and new theoretical approaches that can be used to better predict and analyse the JWST line spectra of protoplanetary discs. We developed a new line escape probability method for disc geometries, and a new scheme for dust settling, and discuss how to apply UV …
AGNs in massive galaxy clusters: Role of galaxy merging, infalling groups, cluster mass, and dynamical state
Koulouridis, E.; Drigga, E.; Gkini, A.
Context. There is compelling evidence that active galactic nuclei (AGNs) in high-density regions have undergone a different evolution than their counterparts in the field, indicating that they are strongly affected by their environment. However, we still lack a comprehensive understanding of the dominant mechanisms that trigger the nucleus and the…
Anatomy of an ionized bubble: NIRCam grism spectroscopy of the z = 6.6 double-peaked Lyman-α emitter COLA1 and its environment
Conroy, Charlie; Sobral, David; Tacchella, Sandro +10 more
The increasingly neutral intergalactic gas at z > 6 impacts the Lyman-α (Lyα) flux observed from galaxies. One luminous galaxy, COLA1, stands out because of its unique double-peaked Lyα line at z = 6.6, unseen in any simulation of reionization. Here, we present JWST/NIRCam wide-field slitless spectroscopy in a 21 arcmin2 field center…
SMILES: A Prototype JWST Multiband Mid-infrared Survey
Shivaei, Irene; Lyu, Jianwei; Alberts, Stacey +4 more
The Mid-Infrared Instrument (MIRI) for JWST is supplied with a suite of imaging band-pass filters optimized for full spectral coverage in eight intermediate-width bands from 5 to 26 µm and a narrower one at 11.3 µm. This contrasts with previous infrared space telescopes, which generally have provided only two broad bands, one near 10 &…
Chemistry of Complex Organic Molecules in the V883 Ori Disk Revealed by ALMA Band 3 Observations
Aikawa, Yuri; Nomura, Hideko; Yamato, Yoshihide +3 more
Complex organic molecules (COMs) in protoplanetary disks are key to understanding the origin of volatiles in comets in our solar system, yet the chemistry of COMs in protoplanetary disks remains poorly understood. Here, we present Atacama Large Millimeter/submillimeter Array Band 3 observations of the disk around the young outbursting star V883 Or…
Hunting for complex cyanides in protostellar ices with the JWST. A tentative detection of CH3CN and C2H5CN
Manoj, P.; van Dishoeck, E. F.; Nazari, P. +20 more
Nitrogen-bearing complex organic molecules have been commonly detected in the gas phase but not yet in interstellar ices. This has led to the long-standing question of whether these molecules form in the gas phase or in ices. The James Webb Space Telescope (JWST) offers the sensitivity, spectral resolution, and wavelength coverage needed to detect…
Metal-poor stars with disc-like orbits. Possible traces of the Galactic disc at very early epochs
Massari, D.; De Angeli, F.; Riello, M. +5 more
We used photometric metallicity estimates for about 700 000 stars in the surroundings of the Sun, with very accurate distances and 3D motions measures from Gaia DR3, to explore the properties of the metal-poor (−2.0 < [Fe/H] ≤ −1.5; MP) and very metal-poor ([Fe/H] ≤ −2.0; VMP) stars with disc kinematics in the sample. We confirm the presence of…