6 research outputs found
Bubbles and outflows: the novel JWST/NIRSpec view of the z=1.59 obscured quasar XID2028
Quasar feedback in the form of powerful outflows is invoked as a key
mechanism to quench star formation in galaxies, although direct observational
evidence is still scarce and debated. Here we present Early Release Science
JWST NIRSpec IFU observations of the z=1.59 prototypical obscured quasar
XID2028: this target represents a unique test case to study QSO feedback at the
peak epoch of AGN-galaxy co-evolution thanks to its existing extensive
multi-wavelength coverage and massive and extended outflow detected both in the
ionised and molecular components. With the unprecedented sensitivity and
spatial resolution of JWST, the NIRSpec dataset reveals a wealth of structures
in the ionised gas kinematics and morphology previously hidden in the
seeing-limited ground-based data. In particular, we find evidence of
interaction between the interstellar medium of the galaxy and the QSO-driven
outflow and radio jet, which is producing an expanding bubble from which the
fast and extended wind detected in previous observations is emerging. The new
observations confirm the complex interplay between the AGN jet/wind and the ISM
of the host galaxy, highlighting the role of low luminosity radio jets in AGN
feedback, and showcase the new window opened by NIRSpec on the detailed study
of feedback at high redshift.Comment: 12 pages, 11 figures, submitted to A&A. Comments welcom
Multiple intra-hepatic and abdominal splenosis: an easy call if you know about it
Hepatic splenosis represents the heterotopic implantation of splenic tissue caused by the spillage of cells from the spleen usually after splenectomy or splenic trauma. This condition is usually an incidental finding during surgery and its real incidence is unknown. Splenic implants, which can be placed anywhere in the abdominal cavity, are usually multiple and may be confused with different benign and malignant conditions such as renal tumors, abdominal lymphomas, and endometriosis. We hereby report an unusual case of multiple abdominal splenosis, with a particular intra-hepatic location, that could be misinterpreted as an hepato-cellular carcinoma
A dusty compact object bridging galaxies and quasars at cosmic dawn
Understanding how super-massive black holes form and grow in the early
Universe has become a major challenge since the discovery of luminous quasars
only 700 million years after the Big Bang. Simulations indicate an evolutionary
sequence of dust-reddened quasars emerging from heavily dust-obscured
starbursts that then transition to unobscured luminous quasars by expelling gas
and dust. Although the last phase has been identified out to a redshift of 7.6,
a transitioning quasar has not been found at similar redshifts owing to their
faintness at optical and near-infrared wavelengths. Here we report observations
of an ultraviolet compact object, GNz7q, associated with a dust-enshrouded
starburst at a redshift of z=7.1899+/-0.0005. The host galaxy is more luminous
in dust emission than any other known object at this epoch, forming 1,600 solar
masses of stars per year within a central radius of 480 parsec. A red point
source in the far-ultraviolet is identified in deep, high-resolution imaging
and slitless spectroscopy. GNz7q is extremely faint in X-rays, which indicates
the emergence of a uniquely ultraviolet compact star-forming region or a
Compton-thick super-Eddington black-hole accretion disk at the dusty starburst
core. In the latter case, the observed properties are consistent with
predictions from cosmological simulations and suggest that GNz7q is an
antecedent to unobscured luminous quasars at later epochs.Comment: 49 pages, 15 figures, 2 tables. Authors' version. Published in the 14
April issue of Natur
MOONS: The New Multi-Object Spectrograph for the VLT
International audienceMOONS is the new Multi-Object Optical and Near-infrared Spectrograph currently under construction for the Very Large Telescope (VLT) at ESO. This remarkable instrument combines, for the first time, the collecting power of an 8-m telescope, 1000 fibres with individual robotic positioners, and both low- and high-resolution simultaneous spectral coverage across the 0.64â1.8Â ÎŒm wavelength range. This facility will provide the astronomical community with a powerful, world-leading instrument able to serve a wide range of Galactic, extragalactic and cosmological studies. Construction is now proceeding full steam ahead and this overview article presents some of the science goals and the technical description of the MOONS instrument. More detailed information on the MOONS surveys is provided in the other dedicated articles in this Messenger issue