Search Publications
The SCUBA-2 Cosmology Legacy Survey: The EGS deep field - II. Morphological transformation and multiwavelength properties of faint submillimetre galaxies
Dunlop, J. S.; Farrah, D.; Michałowski, M. J. +9 more
We present a multiwavelength analysis of galaxies selected at 450 and 850 µm from the deepest SCUBA-2 observations in the Extended Groth Strip (EGS) field, which have an average depth of σ450 = 1.9 and σ850 = 0.46 mJy beam- 1 over ∼70 arcmin2. The final sample comprises 95 sources: 56 (59 per cent)…
Gravitational waves and the polarizations in Hořava gravity after GW170817
Gong, Yungui; Hou, Shaoqi; Papantonopoulos, Eleftherios +1 more
The gravitational waves of Hořava gravity, their polarization states, and their possible observational signatures are discussed. Using the gauge-invariant variable formalism, we find the three polarization modes in Hořava gravity excited by the three physical degrees of freedom contained in this theory. In particular, the scalar degree of freedom …
The geometric distance and binary orbit of PSR B1259-63
Ransom, S. M.; Tomsick, J. A.; Miller-Jones, J. C. A. +8 more
The pulsar/massive star binary system PSR B1259-63/LS 2883 is one of the best-studied gamma-ray binaries, a class of systems whose bright gamma-ray flaring can provide important insights into high-energy physics. Using the Australian Long Baseline Array, we have conducted very long baseline interferometric observations of PSR B1259-63 over 4.4 yea…
A jet model for the fast IR variability of the black hole X-ray binary GX 339-4
Maccarone, Thomas J.; Malzac, Julien; Petrucci, Pierre-Olivier +18 more
Using the simultaneous Infra-Red (IR) and X-ray light curves obtained by Kalamkar et al., we perform a Fourier analysis of the IR/X-ray timing correlations of the black hole X-ray binary (BHB) GX 339-4. The resulting IR vs X-ray Fourier coherence and lag spectra are similar to those obtained in previous studies of GX 339-4 using optical light curv…
Warm-hot gas in X-ray bright galaxy clusters and the H I-deficient circumgalactic medium in dense environments
Bowen, David V.; Tripp, Todd M.; Jenkins, Edward B. +3 more
We analyse the intracluster medium (ICM) and circumgalactic medium (CGM) in seven X-ray-detected galaxy clusters using spectra of background quasi-stellar objects (QSOs) (HST-COS/STIS), optical spectroscopy of the cluster galaxies (MMT/Hectospec and SDSS), and X-ray imaging/spectroscopy (XMM-Newton and Chandra). First, we report a very low coverin…
Multi-episode Chromospheric Evaporation Observed in a Solar Flare
Tian, H.; Chen, N. -H.
With observations of the Interface Region Imaging Spectrograph (IRIS), we study chromospheric heating and evaporation during an M1.6 flare SOL2015-03-12T11:50. At the flare ribbons, the Mg II 2791.59 Å line shows quasi-periodic short-duration red-wing enhancement, which is likely related to repetitive chromospheric condensation as a result of epis…
The low-luminosity accretion disc wind of the black hole transient V4641 Sagittarii
Garcia, Michael R.; Torres, Manuel A. P.; Muñoz-Darias, Teo
We present an optical spectroscopic study of the black hole X-ray transient V4641 Sgr (=SAX J1819.3-2525) covering the 1999, 2002, and 2004 outbursts. The spectra were taken over 22 different epochs during the low-luminosity phases that follow the sharp and bright outburst peaks displayed by the system. The data reveal the frequent presence of win…
A New Probe of Line-of-sight Magnetic Field Tangling
Clark, S. E.
The Galactic neutral hydrogen (H I ) sky at high Galactic latitudes is suffused with linear structure. Particularly prominent in narrow spectral intervals, these linear H I features are well aligned with the plane-of-sky magnetic field orientation as measured with optical starlight polarization and polarized thermal dust emission. We analyze the c…
Disentangling the AGN and star formation connection using XMM-Newton
Georgantopoulos, I.; Magdis, G.; Masoura, V. A. +3 more
There is growing evidence supporting the coeval growth of galaxies and their resident super-massive black hole (SMBH). Most studies also claim a correlation between the activity of the SMBH and the star formation of the host galaxy. It is unclear, however, whether this correlation extends to all redshifts and X-ray luminosities. Some studies find …
With and without spectroscopy: Gaia DR2 proper motions of seven ultra-faint dwarf galaxies
Massari, D.; Helmi, A.
Aims: We present mean absolute proper motion measurements for seven ultra-faint dwarf galaxies orbiting the Milky Way, namely Boötes III, Carina II, Grus II, Reticulum II, Sagittarius II, Segue 2, and Tucana IV. For four of these dwarfs our proper motion estimate is the first ever provided.
Methods: The adopted astrometric data come from…