Search Publications
Extreme-value modelling of the brightest galaxies at z ≳ 9
Silk, Joseph; Heather, Cameron; Chantavat, Teeraparb +1 more
Data from the JWST have revealed an intriguing population of bright galaxies at high redshifts. In this work, we use extreme-value statistics to calculate the distribution [in ultraviolet (UV) magnitude] of the brightest galaxies in the redshift range
Nature of the diffuse emission sources in the H I supershell in the galaxy IC 1613
Egorov, Oleg V.; Yarovova, Anastasiya D.; Gerasimov, Ivan S. +6 more
We present a study of the nearby low-metallicity dwarf galaxy IC 1613, focusing on the search for massive stars and related feedback processes, as well as for faint supernova remnants (SNR) in late stages of evolution. We obtained the deepest images of IC 1613 in the narrow-band H α, He II and [S II] emission lines and new long-slit spectroscopy o…
Measuring the substructure mass power spectrum of 23 SLACS strong galaxy-galaxy lenses with convolutional neural networks
O'Dowd, Matthew; Shajib, Anowar J.; Vernardos, Georgios +3 more
Strong gravitational lensing can be used as a tool for constraining the substructure in the mass distribution of galaxies. In this study we investigate the power spectrum of dark matter perturbations in a population of 23 Hubble Space Telescope images of strong galaxy-galaxy lenses selected from The Sloan Lens ACS (SLACS) survey. We model the dark…
Tracing the evolving X-ray reverberation lags within an individual AGN light curve
Chainakun, P.; Young, A. J.; Nakhonthong, N. +1 more
We present the Granger causality (GC) test for the X-ray reverberation analysis of Active Galactic Nuclei (AGNs). If the light curves in the continuum-dominated band help predict (Granger cause) those dominated by reflection, the Granger lags that associate to the intrinsic reverberation lags can be inferred. We focus on six AGNs observed by XMM-N…
MUSE observations of the optical nebula surrounding the central compact object in the Vela Junior supernova remnant
Safi-Harb, Samar; Ho, Wynn C. G.; Ruiter, Ashley J. +6 more
Central compact objects (CCOs), neutron stars found near the centre of some supernova remnants (SNRs), have been almost exclusively studied in X-rays and are thought to lack the wind nebulae typically seen around young, rotation-powered pulsars. We present the first, spatially resolved, morphological and spectroscopic study of the optical nebula o…
Kinematic study of the Orion Complex: analysing the young stellar clusters from big and small structures
Sánchez-Sanjuán, Sergio; Hernández, Jesús; Pérez-Villegas, Ángeles +4 more
In this work, we analysed young stellar clusters with spatial and kinematic coherence in the Orion star-forming complex. For this study, we selected a sample of pre-main-sequence candidates using parallaxes, proper motions, and positions on the colour-magnitude diagram. After applying a hierarchical clustering algorithm in the 5D parameter space p…
CCD UBV(RI)KC photometry and dynamics of the open cluster NGC 1513
Akkaya Oralhan, İnci; Çakmak, Hikmet; Michel, Raúl +2 more
We derive astrophysical parameters of the open cluster NGC 1513 by means of colour indices built with new CCD UBV(RI)KC photometry. Based on early-type members, the mean foreground reddening and total to selective extinction ratio are E(B - V) = 0.79 ± 0.09 mag and RV = 2.85 ± 0.05. Through the differential grid method, we de…
Unravelling the nuclear dust morphology of NGC 1365: a two-phase polar-RAT model for the ultraviolet to infrared spectral energy distribution
Shalima, P.; Swain, Subhashree; Latha, K. V. P.
We present a 3D radiative transfer model for the spectral energy distribution (SED) of NGC 1365, which is a 'changing look' Seyfert 1.8 type active galactic nucleus (AGN). The SED from the ultraviolet (UV) to the infrared (IR) is constructed using archival data from the Ultra-Violet Imaging Telescope (UVIT) onboard AstroSat, along with IR data fro…
The 3D geometry of reflection nebulae IC 59 and IC 63 with their illuminating star gamma Cas
Lai, Thomas S. -Y.; Witt, Adolf N.; Caputo, Miranda +1 more
The early-type star gamma Cas illuminates the reflection nebulae IC 59 and IC 63, creating two photodissociation regions (PDRs). Uncertainties about the distances to the nebulae and the resulting uncertainty about the density of the radiation fields incident on their surfaces have hampered the study of these PDRs during the past three decades. We …
X-ray measurement of a high-mass white dwarf and its spin for the intermediate polar IGR J18434-0508
Hare, Jeremy; Mukai, Koji; Tomsick, John A. +8 more
IGR J18434-0508 is a Galactic Intermediate Polar (IP) type Cataclysmic Variable (CV) previously classified through optical spectroscopy. The source is already known to have a hard Chandra spectrum. In this paper, we have used follow-up XMM-Newton and NuSTAR observations to measure the white dwarf (WD) mass and spin period. We measure a spin period…