Search Publications
The star formation rates of QSOs
Andreani, P.; Ivison, R. J.; Clements, D. L. +13 more
We examine the far-infrared (FIR) properties of a sample of 5391 optically selected QSOs in the 0.5 < z < 2.65 redshift range down to log [νLν, 2500(erg s-1)] > 44.7, using SPIRE data from Herschel-ATLAS. We split the sample in a grid of 74 luminosity-redshift bins and compute the average optical-IR spectral energy d…
High resolution X-ray spectroscopy of V4641 Sgr during its 2020 outburst
Heinke, C. O.; Miller, J. M.; Gandhi, P. +7 more
We observed the Galactic black hole X-ray binary V4641 Sgr with the high resolution transmission gratings on Chandra during the source's 2020 outburst. Over two epochs of Chandra gratings observations, we see numerous highly ionized metal lines, superimposed on a hot, disc-dominated X-ray continuum. The measured inner disc temperatures and luminos…
SHARP - VIII. J0924+0219 lens mass distribution and time-delay prediction through adaptive-optics imaging
Treu, Tommaso; Lagattuta, David J.; Fassnacht, Christopher D. +6 more
Strongly lensed quasars can provide measurements of the Hubble constant (H0) independent of any other methods. One of the key ingredients is exquisite high-resolution imaging data, such as Hubble Space Telescope (HST) imaging and adaptive-optics (AO) imaging from ground-based telescopes, which provide strong constraints on the mass dist…
V392 Persei: A γ-ray bright nova eruption from a known dwarf nova
Boyd, D.; Starrfield, S.; Page, K. L. +57 more
V392 Persei is a known dwarf nova (DN) that underwent a classical nova eruption in 2018. Here we report ground-based optical, Swift UV and X-ray, and Fermi-LAT γ-ray observations following the eruption for almost three years. V392 Per is one of the fastest evolving novae yet observed, with a t2 decline time of 2 d. Early spectra present…
Polycyclic Aromatic Hydrocarbon emission model in photodissociation regions - I. Application to the 3.3, 6.2, and 11.2 µm bands
Cami, Jan; Tielens, A. G. G. M.; Peeters, Els +1 more
We present a charge distribution based model that computes the infrared spectrum of polycyclic aromatic hydrocarbon (PAH) molecules using recent measurements or quantum chemical calculations of specific PAHs. The model is applied to a sample of well-studied photodissociation regions (PDRs) with well-determined physical conditions (the radiation fi…
Super-Eddington accretion of the first Galactic ultra-luminous X-ray pulsar Swift J0243.6+6124
Zhang, Shu; Li, Xiaobo; Liu, Jiren +6 more
We present a detailed timing study of the pulse profile of Swift J0243.6+6124 with Hard X-ray Modulation Telescope (HXMT) and Fermi/GBM (Gamma-ray Burst Monitor) data during its 2017 giant outburst. The double-peak profile at luminosity above 5 × 1038 erg s-1 is found to be 0.25 phase offset from that below 1.5 × 1038
Morphokinematic modelling of the point-symmetric Cat's Eye, NGC 6543: Ring-like remnants of a precessing jet
Steffen, Wolfgang; Koning, Nico; Clairmont, Ryan
The planetary nebula known as the Cat's Eye Nebula (NGC 6543) has a complex, point-symmetric morphology that cannot be fully explained by the current theory of planetary nebula formation, the interacting stellar winds model. In order to reveal the 3D structure of the Cat's Eye Nebula, we created a detailed 3D morphokinematic model of this nebula u…
Is Terzan 5 the remnant of a building block of the Galactic bulge? Evidence from APOGEE
Cohen, Roger E.; Bizyaev, Dmitry; Pan, Kaike +16 more
It has been proposed that the globular cluster-like system Terzan 5 is the surviving remnant of a primordial building block of the Milky Way bulge, mainly due to the age/metallicity spread and the distribution of its stars in the α-Fe plane. We employ Sloan Digital Sky Survey data from the Apache Point Observatory Galactic Evolution Experiment to …
The complex globular cluster system of the S0 galaxy NGC 4382 in the outskirts of the Virgo Cluster
Cortesi, Arianna; Chies-Santos, Ana L.; Mendes de Oliveira, Claudia +10 more
NGC 4382 is a merger-remnant galaxy that has been classified as morphological type E2, S0, and even Sa. In this work, we performed a photometric and spectroscopic analysis of the globular cluster (GC) system of this peculiar galaxy in order to provide additional information about its history. We used a combination of photometric data in different …
The lively accretion disc in NGC 2992 - II. The 2019/2021 X-ray monitoring campaigns
Bianchi, S.; De Marco, B.; Matt, G. +8 more
We report on the short- and long-term X-ray properties of the bright nearby Seyfert 2 galaxy NGC 2992, which was extensively observed with Swift, XMM-Newton, and NuSTAR. Swift targeted the source more than 100 times between 2019 and 2021 in the context of two monitoring campaigns. Both time-averaged and time-resolved analyses are performed, and we…