Search Publications
A strong lensing model of the galaxy cluster PSZ1 G311.65-18.48
Brammer, G.; Grillo, C.; Tozzi, P. +10 more
We present a strong lensing analysis of the galaxy cluster PSZ1 G311.65-18.48 (z = 0.443) using multi-band observations with Hubble Space Telescope complemented with VLT/MUSE spectroscopic data. The MUSE observations provide redshift estimates for the lensed sources and help to reduce misidentification of the multiple images. Spectroscopic data ar…
The unusual widespread solar energetic particle event on 2013 August 19. Solar origin and particle longitudinal distribution
Williams, D.; Jian, L. K.; Rodríguez-Pacheco, J. +11 more
Context. Late on 2013 August 19, STEREO-A, STEREO-B, MESSENGER, Mars Odyssey, and the L1 spacecraft, spanning a longitudinal range of 222° in the ecliptic plane, observed an energetic particle flux increase. The widespread solar energetic particle (SEP) event was associated with a coronal mass ejection (CME) that came from a region located near th…
Intense dB/dt Variations Driven by Near Earth Bursty Bulk Flows (BBFs): A Case Study
Dunlop, Malcolm W.; Wei, Dong; Yang, Junying +3 more
During geomagnetically disturbed times the surface geomagnetic field often changes abruptly, producing geomagnetically induced currents (GICs) in a number of ground based systems. There are, however, few studies reporting GIC effects which are driven directly by bursty bulk flows (BBFs) in the inner magnetosphere. In this study, we investigate the…
Characterizing the target selection pipeline for the Dark Energy Spectroscopic Instrument Bright Galaxy Survey
Baugh, Carlton M.; Myers, Adam D.; Moustakas, John +18 more
We present the steps taken to produce a reliable and complete input galaxy catalogue for the Dark Energy Spectroscopic Instrument (DESI) Bright Galaxy Survey (BGS) using the photometric Legacy Survey DR8 DECam. We analyse some of the main issues faced in the selection of targets for the DESI BGS, such as star-galaxy separation, contamination by fr…
New mass-loss rates of B supergiants from global wind models
Krtička, J.; Kubát, J.; Krtičková, I.
Massive stars lose a significant fraction of mass during their evolution. However, the corresponding mass-loss rates are rather uncertain, especially for evolved stars. To improve this, we calculated global line-driven wind models for Galactic B supergiants. Our models predict radial wind structure and particularly the mass-loss rates and terminal…
Are Massive Dense Clumps Truly Subvirial? A New Analysis Using Gould Belt Ammonia Data
Caselli, Paola; Di Francesco, James; Rosolowsky, Erik +22 more
Dynamical studies of dense structures within molecular clouds often conclude that the most massive clumps contain too little kinetic energy for virial equilibrium, unless they are magnetized to an unexpected degree. This raises questions about how such a state might arise, and how it might persist long enough to represent the population of massive…
The GALAH survey and symbiotic stars - I. Discovery and follow-up of 33 candidate accreting-only systems
Freeman, K. C.; Masetti, N.; Munari, U. +14 more
We have identified a first group of 33 new candidates for symbiotic stars (SySt) of the accreting-only variety among the 600 255 stars so far observed by the GALactic Archaeology with HERMES (GALAH) high-resolution spectroscopic survey of the Southern hemisphere, more than doubling the number of those previously known. GALAH aims to high latitudes…
SMARPs and SHARPs: Two Solar Cycles of Active Region Data
Sun, Xudong; Bobra, Monica G.; Wright, Paul J. +1 more
We present a new data product, called Space-Weather MDI Active Region Patches (SMARPs), derived from maps of the solar surface magnetic field taken by the Michelson Doppler Imager on board the Solar and Heliospheric Observatory. Together with the Space-Weather HMI Active Region Patches (SHARPs), derived from similar maps taken by the Helioseismic …
BG Ind: the nearest doubly eclipsing, compact hierarchical quadruple system
Vanderburg, A.; Maxted, P. F. L.; Blackford, M. G. +9 more
BG Ind is a well-studied, bright, nearby binary consisting of a pair of F stars in a 1.46-d orbit. We have discovered in the TESS light curve for TIC 229804573 (aka BG Ind), a second eclipsing binary in the system with a 0.53-d period. Our subsequent analyses of the recent TESS and archival ground-based photometric and radial velocity (RV) data re…
On a Possible Solution to the Tidal Realignment Problem for Hot Jupiters
Winn, Joshua N.; Penev, Kaloyan; Anderson, Kassandra R.
Hot stars with hot Jupiters have a wide range of obliquities, while cool stars with hot Jupiters tend to have low obliquities. An enticing explanation for this pattern is tidal realignment of the cool host stars, although this explanation assumes that obliquity damping occurs faster than orbital decay, an assumption that needs further exploration.…