Search Publications
Climbing the cosmic ladder with stellar twins
Gilmore, G.; Soubiran, C.; Jofré, P. +3 more
Distances to stars are key to revealing a three-dimensional view of the Milky Way, yet their determination is a major challenge in astronomy. Whilst the brightest nearby stars benefit from direct parallax measurements, fainter stars are subject of indirect determinations with uncertainties exceeding 30 per cent. We present an alternative approach …
Morphological evolution in situ: disc-dominated cluster red sequences at z ∼ 1.25
De Propris, Roberto; Phillipps, Steven; Bremer, Malcolm N.
We have carried out a joint photometric and structural analysis of red sequence galaxies in four clusters at a mean redshift of <z> ∼ 1.25 using optical and near-infrared Hubble Space Telescope imaging reaching to at least three magnitudes fainter than M*. As expected, the photometry and overall galaxy sizes imply purely passive evolution of…
A blind CO detection of a distant red galaxy in the HS1700+64 protocluster.
Smail, I.; Ivison, R. J.; Gurwell, M. +7 more
We report the blind detection of 12CO emission from a distant red galaxy, HS1700.DRG55. We have used the IRAM Plateau de Bure Interferometer WideX, with its 3.6 GHz of instantaneous dual-polarization bandwidth, to target 12CO(3-2) from galaxies lying in the protocluster at z = 2.300 in the field HS1700+64. If indeed this line…
Co-evolution of black hole growth and star formation from a cross-correlation analysis between quasars and the cosmic infrared background
Ross, Nicholas P.; Wang, Wenting; Han, Jiaxin +19 more
We present the first cross-correlation measurement between Sloan Digital Sky Survey type 1 quasars and the cosmic infrared background (CIB) measured by Herschel. The quasars cover the redshift range 0.15 < z < 3.5 where most of the CIB originates. We detect the sub-millimetre emission of the quasars, which dominates on small scales, and corr…
HH 666: different kinematics from H α and [Fe II] emission provide a missing link between jets and outflows
Smith, Nathan; Bally, John; Reiter, Megan +1 more
HH 666 is an externally irradiated protostellar outflow in the Carina nebula for which we present new near-IR [Fe II] spectra obtained with the Folded-Port Infrared Echellette spectrograph at Magellan Observatory. Earlier H α and near-IR [Fe II] imaging revealed that the two emission lines trace substantially different morphologies in the inner ∼4…
Missing hard states and regular outbursts: the puzzling case of the black hole candidate 4U 1630-472
Capitanio, F.; Ferrigno, C.; Campana, R. +1 more
4U 1630-472 is a recurrent X-ray transient classified as a black hole candidate from its spectral and timing properties. One of the peculiarities of this source is the presence of regular outbursts with a recurrence period between 600 and 730 d that has been observed since the discovery of the source in 1969. We report on a comparative study of th…
High-energy emission processes in M87
Tramacere, A.; Beckmann, V.; Soldi, S. +2 more
We study the contribution of thermal and non-thermal processes to the inverse Compton emission of the radio galaxy M87 by modelling its broad-band emission. Through this we aim to derive insight into where within the AGN the X-ray, γ-ray and VHE emission is produced. We have analysed all available INTEGRAL IBIS/ISGRI (Imager on Board INTEGRAL Spac…
Relativistic Fe Kα line revealed in the composite X-ray spectrum of narrow-line Seyfert 1 galaxies - do their black holes have averagely low or intermediate spins?
Lu, Youjun; Liu, Zhu; Yuan, Weimin +1 more
While a broad profile of the Fe Kα emission line is frequently found in the X-ray spectra of typical Seyfert galaxies, the situation is unclear in the case of narrow-line Seyfert 1 galaxies (NLS1s) - an extreme subset which are generally thought to harbour less massive black holes with higher accretion rates. In this paper, the ensemble property o…
Spatially resolved kinematic observations of the planetary nebulae Hen 3-1333 and Hen 2-113.
Parker, Q. A.; Danehkar, A.
We have performed integral field spectroscopy of the planetary nebulae Hen 3-1333 (PNG332.9-09.9) and Hen 2-113 (PNG321.0+03.9), which are unusual in exhibiting dual-dust chemistry and multipolar lobes but also ionized by late-type [WC 10] central stars. The spatially resolved velocity distributions of the Hα emission line were used to determine t…
Discovery of true, likely and possible symbiotic stars in the dwarf spheroidal NGC 205
Gonçalves, Denise R.; Akras, Stavros; Magrini, Laura +1 more
In this paper we discuss the photometric and spectroscopic observations of newly discovered (symbiotic) systems in the dwarf spheroidal galaxy NGC 205. The Gemini Multi-Object Spectrograph on-off band [O III] 5007 Å emission imaging highlighted several [O III] line emitters, for which optical spectra were then obtained. The detailed study of the s…