Search Publications
Inflowing gas in the central parsec of M81
Devereux, Nick
Spectroscopic observations of the Seyfert 1/Liner nucleus of M81, obtained recently with the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope(HST), have revealed an ultraviolet (UV)-visible spectrum rich with emission lines of a variety of widths, ionization potentials, and critical densities, including several in the UV that…
Tiny grains shining bright in the gaps of Herbig Ae transitional discs
Monnier, John D.; Kraus, Stefan; Federrath, Christoph +7 more
This work presents a study of two Herbig Ae transitional discs, Oph IRS 48 and HD 169142; which both have reported rings in their dust density distributions. We use Keck-II/NIRC2 adaptive optics imaging observations in the L' filter (3.8 µm) to probe the regions of these discs inwards of {∼ }20 au from the star. We introduce our method for i…
The 2018 eruption and long-term evolution of the new high-mass Herbig Ae/Be object Gaia-18azl = VES 263
Munari, U.; Banerjee, D. P. K.; Čotar, K. +10 more
We have been monitoring, at high cadence, the photometric and spectroscopic evolution of VES 263 following the discovery in 2018 of a brightening labelled as event Gaia-18azl. VES 263 is so far a neglected emission-line object discovered in the 1960s on objective prism plates, tentatively classified as a semiregular AGB cool giant by automated ana…
Observational determination of the galaxy bias from cosmic variance with a random pointing survey: clustering of z ∼ 2 galaxies from Hubble's BoRG survey
Cameron, Alex J.; Livermore, Rachael C.; Trenti, Michele +1 more
Gravitational clustering broadens the count-in-cells distribution of galaxies for surveys along uncorrelated (well-separated) lines of sight beyond Poisson noise. A number of methods have proposed to measure this excess `cosmic' variance to constrain the galaxy bias (i.e. the strength of clustering) independently of the two-point correlation funct…
A nuclear ionized gas outflow in the Seyfert 2 galaxy UGC 2024
Robinson, Andrew; Schnorr-Müller, Allan; Storchi-Bergmann, Thaisa +15 more
As part of a high-resolution observational study of feeding and feedback processes occurring in the vicinity of the active galactic nucleus in 40 galaxies, we observed the inner 3{^''.}5 × 5 arcsec of the nearby spiral and Seyfert 2 galaxy UGC 2024 with the integral field unit of the Gemini-South Telescope. The observations enabled a st…
Detailed spectroscopic and photometric study of three detached eclipsing binaries
Kahraman Aliçavuş, F.; Aliçavuş, F.
Detached eclipsing binaries are remarkable systems to provide accurate fundamental stellar parameters. Fundamental stellar parameters and the metallicity values of stellar systems are needed to deeply understand stellar evolution and formation. In this study, we focus on the detailed spectroscopic and photometric studies of three detached eclipsin…
Search for the evolutionary relationship between Galactic globular and open clusters using data from the Gaia DR2 catalogue
Bobylev, V. V.; Bajkova, A. T.
Passing through the Galactic disc, a massive object such as a globular cluster, can trigger star formation process leading to the birth of open clusters. Here, we analyse such possible evolutionary relationship between globular and open clusters. To search for the closest rapprochement between objects we computed backwards the orbits of 150 Galact…
Long-term X-ray variation of the colliding-wind Wolf-Rayet binary WR 125
Sugawara, Yasuharu; Ebisawa, Ken; Midooka, Takuya
WR 125 is considered to be a colliding-wind Wolf-Rayet binary (CWWB), from which the most recent infrared flux increase was reported between 1990 and 1993. We observed the object four times from 2016 November to 2017 May with Swift and XMM-Newton, and carried out a precise X-ray spectral study for the first time. There were hardly any changes in t…
Radio-optical galaxy shape and shear correlations in the COSMOS field using 3 GHz VLA observations
Brown, Michael L.; Harrison, Ian; Hillier, Tom +1 more
We present a weak-lensing analysis of the 3 GHz Very Large Array radio survey of the COSMOS field, which we correlate with overlapping Hubble Space Telescope-Advanced Camera for Survey optical observations using both intrinsic galaxy shape and cosmic shear correlation statistics. After cross-matching sources between the two catalogues, we measure …
A slowly expanding torus associated with the candidate LBV MGE 042.0787+00.5084
Bordiu, Cristobal; Rizzo, J. Ricardo; Ritacco, Alessia
The luminous blue variable (LBV) phase is a poorly understood stage in the evolution of high-mass stars, characterized by its brevity and instability. The surroundings of LBV stars are excellent test beds to study their dense stellar winds and eruptive mass-loss events. Aiming to improve our knowledge of the LBV phase, we observed the J = 1 → 0 an…