Search Publications
COSMOS2020: Investigating the AGN-obscured accretion phase at z ∼ 1 via [Ne V] selection
Pozzi, F.; Lapi, A.; Vignali, C. +7 more
The black hole-and-galaxy (BH-galaxy) co-evolution paradigm predicts a phase where most of the star formation (SF) and BH accretion takes place in gas-rich environments, namely, in what are likely to be very obscured conditions. In the first phase of this growth, some of the galactic gas is funnelled toward the centre of the galaxy and is accreted…
Revisiting the effect of lens mass models in cosmological applications of strong gravitational lensing
Harvey-Hawes, Christopher; Wiltshire, David L.
Strong gravitational lens system catalogues are typically used to constrain a combination of cosmological and empirical power-law lens mass model parameters, often introducing additional empirical parameters and constraints from high resolution imagery. We investigate these lens models using Bayesian methods through a novel alternative that treats…
Filter Design for Estimation of Stellar Metallicity: Insights from Experiments with Gaia XP Spectra
Xiang, Maosheng; Huang, Yang; Liu, Jifeng +11 more
We search for an optimal filter design for the estimation of stellar metallicity, based on synthetic photometry from Gaia XP spectra convolved with a series of filter-transmission curves defined by different central wavelengths and bandwidths. Unlike previous designs based solely on maximizing metallicity sensitivity, we find that the optimal solu…
An Algorithm to Mitigate Charge Migration Effects in Data from the Near Infrared Imager and Slitless Spectrograph on the James Webb Space Telescope
Volk, Kevin; Bushouse, Howard; Goudfrooij, Paul +1 more
We present an algorithm that mitigates the effects of charge migration due to the "brighter-fatter effect" (BFE) that occurs for highly illuminated stars in the Teledyne HAWAII-2RG detectors used in the NIRCam, NIRISS, and NIRSpec science instruments aboard the James Webb Space Telescope (JWST). The impact of this effect is most significant for ph…
Propagation of untwisting solar jets from the low-beta corona into the super-Alfvénic wind: Testing a solar origin scenario for switchbacks
Pariat, E.; Froment, C.; Wyper, P. F. +3 more
Context. Parker Solar Probe's (PSP) discovery of the prevalence of switchbacks (SBs), localised magnetic deflections in the nascent solar wind, has sparked interest in uncovering their origins. A prominent theory suggests these SBs originate in the lower corona through magnetic reconnection processes, closely linked to solar jet phenomena. Jets ar…
Viewing the PLATO LOPS2 field through the lenses of TESS
Bayliss, Daniel; Pelisoli, Ingrid; Kunimoto, Michelle +3 more
PLATO will begin observing stars in its Southern Field (LOPS2) after its launch in late 2026. By this time, TESS will have observed the stars in LOPS2 for at least four years. We find that by 2025, on average each star in the PLATO field will have been monitored for 330 d by TESS, with a subset of stars in the TESS continuous viewing zone having o…
JWST reveals a high fraction of disk breaks at 1 ≤ z ≤ 3
Xu, Dewang; Yu, Si-Yue
We analyzed the deconvolved surface brightness profiles of 247 massive and angularly large disk galaxies at 1 ≤ z ≤ 3 to study high-redshift disk breaks, using F356W-band images from the Cosmic Evolution Early Release Science survey (CEERS). We found that 12.6% of these galaxies exhibit type I (exponential) profiles, 56.7% exhibit type II (down-be…
Transitions in magnetic behavior at the substellar boundary
Stelzer, B.; Raetz, St.; Magaudda, E. +3 more
We aim to advance our understanding of magnetic activity and the underlying dynamo mechanism at the end of the main sequence. To this end, we have embarked on collecting simultaneous X-ray and radio observations for a sample of M7..L0 dwarfs in the solar neighborhood using XMM-Newton jointly with the Jansky Very Large Array (JVLA) and the Australi…
Constraining Free–Free Emission and Photoevaporative Mass-loss Rates for Known Proplyds and New VLA–identified Candidate Proplyds in NGC 1977
Eisner, Josh A.; Boyden, Ryan D.
We present NSF's Karl G. Jansky Very Large Array observations covering the NGC 1977 region at 3.0, 6.4, and 15.0 GHz. We search for compact radio sources and detect continuum emission from 34 NGC 1977 cluster members and 37 background objects. Of the 34 radio-detected cluster members, 3 are associated with known proplyds in NGC 1977, 22 are associ…
Hitomi HXT deconvolution imaging of the Crab Nebula dazzled by the Crab pulsar
Maeda, Yoshitomo; Ishida, Manabu; Awaki, Hisamitsu +3 more
We develop a new deconvolution method to recover the precise Crab Nebula image taken by the Hitomi HXT, suppressing the artifact due to the bright Crab pulsar. We extend the Richardson-Lucy method, introducing two components corresponding to the nebula and pulsar with regularization for smoothness and flux, respectively, and performing simultaneou…