Search Publications
Signature of the turbulent component of the solar dynamo on active region scales and its association with flaring activity
Abramenko, Valentina I.
It is a challenging problem to obtain observational evidence of the turbulent component of solar dynamo operating in the convective zone because the dynamo action is hidden below the photosphere. Here we present results of a statistical study of flaring active regions (ARs) that produced strong solar flares of an X-ray class X1.0 and higher during…
The velocity dispersion function of early-type galaxies and its redshift evolution: the newest results from lens redshift test
Liu, Yuting; Cao, Shuo; Biesiada, Marek +3 more
The redshift distribution of galactic-scale lensing systems provides a laboratory to probe the velocity dispersion function (VDF) of early-type galaxies (ETGs) and measure the evolution of ETGs at redshift z ~ 1. Through the statistical analysis of the currently largest sample of ETG gravitational lenses, we conclude that the VDF inferred solely f…
Black hole mass measurement using ALMA observations of [CI] and CO emissions in the Seyfert 1 galaxy NGC 7469
Baba, Shunsuke; Meier, David S.; Turner, Jean L. +11 more
We present a supermassive black hole (SMBH) mass measurement in the Seyfert 1 galaxy NGC 7469 using Atacama Large Millimeter/submillimeter Array (ALMA) observations of the atomic-[CI](1-0) and molecular-12CO(1-0) emission lines at the spatial resolution of ≈0${_{.}^{\prime\prime}}$3 (or ≈100 pc). These emissions reveal that NGC 7469 hos…
The Cosmic Ultraviolet Baryon Survey (CUBS) - IV. The complex multiphase circumgalactic medium as revealed by partial Lyman limit systems
Faucher-Giguère, Claude-André; Johnson, Sean D.; Petitjean, Patrick +18 more
We present a detailed study of two partial Lyman limit systems (pLLSs) of neutral hydrogen column density $N_\mathrm{H\, I}\approx (1-3)\times 10^{16}\, \mathrm{cm}^{-2}$ discovered at $z$ = 0.5 in the Cosmic Ultraviolet Baryon Survey (CUBS). Available far-ultraviolet spectra from the Hubble Space Telescope Cosmic Origins Spectrograph and optical …
High-resolution ALMA and HST images of q1 Eri: an asymmetric debris disc with an eccentric Jupiter
Krist, J.; Stapelfeldt, K.; Kral, Q. +10 more
We present Atacama Large Millimetre/sub-Millimetre Array (ALMA) 1.3 and 0.86 mm observations of the nearby (17.34 pc) F9V star q1 Eri (HD 10647, HR 506). This system, with age ~1.4 Gyr, hosts a ~2 au radial velocity planet and a debris disc with the highest fractional luminosity of the closest 300 FGK type stars. The ALMA images, with resolution ~…
Tidal tails in the disintegrating open cluster NGC 752
Vaidya, Kaushar; Rao, Khushboo K.; Agarwal, Manan +1 more
We utilize the robust membership determination algorithm, ML-MOC, on the precise astrometric and deep photometric data from Gaia Early Data Release 3 within a region of radius 5° around the centre of the intermediate-age Galactic open cluster NGC 752 to identify its member stars. We report the discovery of the tidal tails of NGC 752, extending out…
WISDOM project - VII. Molecular gas measurement of the supermassive black hole mass in the elliptical galaxy NGC 7052
Williams, Thomas G.; Sarzi, Marc; Cappellari, Michele +7 more
Supermassive black hole (SMBH) masses can be measured by resolving the dynamical influences of the SMBHs on tracers of the central potentials. Modern long-baseline interferometers have enabled the use of molecular gas as such a tracer. We present here Atacama Large Millimeter/submillimeter Array observations of the elliptical galaxy NGC 7052 at 0.…
A method for finding anomalous astronomical light curves and their analogues
Graham, Matthew J.; Giles, Daniel; Mahabal, Ashish A. +4 more
Our understanding of the Universe has profited from deliberate targeted studies of known phenomena, as well as from serendipitous unexpected discoveries, such as the discovery of a complex variability pattern in the direction of KIC 8462852 (Boyajian's star). Upcoming surveys such as the Vera C. Rubin Observatory Legacy Survey of Space and Time wi…
The centres of M83 and the Milky Way: opposite extremes of a common star formation cycle
Henshaw, Jonathan D.; Kruijssen, J. M. Diederik; Longmore, Steven N. +8 more
In the centres of the Milky Way and M83, the global environmental properties thought to control star formation are very similar. However, M83's nuclear star formation rate (SFR), as estimated by synchrotron and H α emission, is an order of magnitude higher than the Milky Way's. To understand the origin of this difference we use ALMA observations o…
Locating the gamma-ray emission region in the brightest Fermi-LAT flat-spectrum radio quasars
Brown, Anthony M.; Acharyya, Atreya; Chadwick, Paula M.
We present a temporal and spectral analysis of the gamma-ray flux from nine of the brightest flat-spectrum radio quasars (FSRQs) detected with the Fermi Large Area Telescope during its first 8 yr of operation, with the aim of constraining the location of the emission region. Using the increased photon statistics obtained from the two brightest fla…