Search Publications
About AGN ionization echoes, thermal echoes and ionization deficits in low-redshift Lyα blobs
Torrey, Paul; Fu, Hai; Davies, Rebecca L. +7 more
We report the discovery of 14 Lyα blobs (LABs) at z ∼ 0.3, existing at least 4-7 billion years later in the Universe than all other LABs known. Their optical diameters are 20-70 kpc, and GALEX data imply Lyα luminosities of (0.4-6.3) × 1043 erg s-1. Contrary to high-z LABs, they live in low-density areas. They are ionized by …
The infrared luminosities of ∼332 000 SDSS galaxies predicted from artificial neural networks and the Herschel Stripe 82 survey
Ellison, Sara L.; Mendel, J. Trevor; Rosario, David J. +1 more
The total infrared (IR) luminosity (LIR) can be used as a robust measure of a galaxy's star formation rate (SFR), even in the presence of an active galactic nucleus (AGN), or when optical emission lines are weak. Unfortunately, existing all sky far-IR surveys, such as the Infrared Astronomical Satellite (IRAS) and AKARI, are relatively …
How well can we measure supermassive black hole spin?
Gallo, L. C.; Bonson, K.
Being one of only two fundamental properties black holes possess, the spin of supermassive black holes (SMBHs) is of great interest for understanding accretion processes and galaxy evolution. However, in these early days of spin measurements, consistency and reproducibility of spin constraints have been a challenge. Here, we focus on X-ray spectra…
Detection of a second high-velocity component in the highly ionized wind from PG 1211+143
Vaughan, Simon; Reeves, James; Pounds, Ken +1 more
An extended XMM-Newton observation of the luminous narrow line Seyfert galaxy PG1211+143 in 2014 has revealed a more complex highly ionized, high-velocity outflow. The detection of previously unresolved spectral structure in Fe K absorption finds a second outflow velocity component of the highly ionized wind, with an outflow velocity of v ∼ 0.066 …
Far-reaching dust distribution in galaxy discs
De Looze, Ilse; Baes, Maarten; Bendo, George J. +21 more
In most studies of dust in galaxies, dust is only detected from its emission to approximately the optical radius of the galaxy. By combining the signal of 110 spiral galaxies observed as part of the Herschel Reference Survey, we are able to improve our sensitivity by an order of magnitude over that for a single object. Here we report the direct de…
The INTEGRAL/IBIS AGN catalogue: an update
Bird, A. J.; Ubertini, P.; Landi, R. +4 more
In the most recent IBIS survey based on observations performed during the first 1000 orbits of INTEGRAL, are listed 363 high-energy emitters firmly associated with AGN, 107 of which are reported here for the first time. We have used X-ray data to image the IBIS 90 per cent error circle of all the AGN in the sample of 107, in order to obtain the co…
Discovery of spin-up in the X-ray pulsar companion of the hot subdwarf HD 49798
Pintore, Fabio; Mereghetti, Sandro; Esposito, Paolo +4 more
The hot subdwarf HD 49798 has an X-ray emitting compact companion with a spin-period of 13.2 s and a dynamically measured mass of 1.28 ± 0.05 M⊙, consistent with either a neutron star or a white dwarf. Using all the available XMM-Newton and Swift observations of this source, we could perform a phase-connected timing analysis extending b…
A SINFONI view of the nuclear activity and circumnuclear star formation in NGC 4303
Colina, L.; Storchi-Bergmann, T.; Riffel, Rogemar A. +8 more
We present new maps of emission-line flux distributions and kinematics in both ionized (traced by H I and [Fe II] lines) and molecular (H2) gas of the inner 0.7 × 0.7 kpc2 of the galaxy NGC 4303, with a spatial resolution 40-80 pc and velocity resolution 90-150 km s- 1 obtained from near-IR integral field spectrosc…
The fossil wind structures of Eta Carinae: changes across one 5.54-yr cycle
Hamaguchi, Kenji; Corcoran, Michael; Moffat, Anthony F. J. +11 more
Eta Carinae, the closest, active, massive binary containing a highly unstable Luminous Blue Variable, exhibits expanding, compressed wind shells, seen in emission, that are spatially and spectrally resolved by Hubble Space Telescope/Space Telescope Imaging Spectrograph. Starting in 2009 June, these structures were mapped across its 5.54-yr, highly…
H I-deficient galaxies in intermediate-density environments
Koribalski, B. S.; Dénes, H.; Wong, O. I. +1 more
Observations show that spiral galaxies in galaxy clusters tend to have on average less neutral hydrogen (H I) than galaxies of the same type and size in the field. There is accumulating evidence that such H I-deficient galaxies are also relatively frequent in galaxy groups. An important question is that which mechanisms are responsible for the gas…