Found 5 talks width keyword sub-millimetre galaxy

Tuesday April 18, 2023
Dr. Ismael García Bernete
University of Oxford



Nowadays, it is widely accepted that most galaxies undergo an active phase in their evolution. The impact of the energy released by active galactic nuclei (AGN) in the interstellar medium (ISM) of the host galaxy has been proposed as a key mechanism responsible for regulating star formation (SF). The mid-infrared (IR) is the ideal spectral range to investigate the nuclear/circumnuclear regions of AGN since dust extinction is significantly lower compared to the visible range. Furthermore, it provides unique tracers to study the AGN-SF connection such as H2 rotational lines, fine structure lines and Polycyclic Aromatic Hydrocarbons (PAHs). PAHs are also a powerful tool to characterize the ISM in different environments.

Recently, we presented new JWST/MIRI MRS spectroscopy of three Seyfert AGN in which we compare their nuclear PAH emission with that of star-forming regions. This study represents the first of its kind to use sub-arcsecond angular resolution data of local luminous Seyferts (Lbol > 10^44.5 erg/s) with a wide wavelength coverage (4.9-28.1 μm). Our results showed that a suite of PAH features is present in the innermost parts of these Seyfert galaxies. We found that the nuclear regions of AGN lie at different positions of the PAH diagnostic diagrams, whereas the SF regions are concentrated around the average values of SF galaxies. Furthermore, we find that the nuclear PAH emission mainly originates in neutral PAHs while, in contrast, PAH emission originating in the star forming regions favours small ionised PAH grains. Therefore, our results provide evidence that the AGN have a significant impact on the ionization state and size of the PAH grains on scales of ~142-245 pc. This is fundamental since PAH bands are routinely used to measure star-formation activity in near and far SF and active galaxies.

Finally, I will summarise our ongoing JWST work within the GATOS (Galactic Activity, Torus and Outflow Survey) collaboration. In particular, I will focus on our recent study about the survival of PAH molecules in AGN-driven outflows.

Thursday May 27, 2021
Dr. Manuela Bischetti


This talk will be dedicated to luminous (LBol~1E47 erg/s),
high-redshift quasars, which are ideal targets to investigate (i) feedback
from SMBHs, and (ii) the early growth phases of giant galaxies. I will
present evidence of  SMBH-driven outflows  at all Cosmic epochs, back to
the early Universe. These outflows involve all gas phases (molecular,
neutral, ionised) and extend on nuclear to galactic and circum-galactic
scales. I will report on the first systematic study of the molecular gas
properties in the host-galaxies of the most luminous quasars, fundamental
to probe the impact of SMBH feedback on the host-galaxy evolution. I will
show that luminous quasars pinpoint high-density sites where giant galaxies
assemble, and I will discuss the major contribution of mergers to the final
galaxy mass. To this aim, I will present a wealth of multi-wavelength (UV
to sub-millimeter) observations from the WISE/SDSS hyper-luminous quasars
survey  at z~2-5 (WISSH), and recent results from the ESO large program
XQR-30, the Ultimate X-SHOOTER Legacy Survey of Quasars at the Reionization


Thursday June 13, 2013
Dr. Itziar Aretxaga


AzTEC is a sensitive bolometer camera that, coupled with 10-15m-class sub-mm telescopes, has mapped more than 3 sq. deg of the extragalactic sky to depths between 0.7 and 1.1 mJy at 1.1mm, prior to its current installation and operation on the 32m Large Millimeter Telescope (LMT). These extragalactic surveys targeted towards blank-fields and biased high-z environments alike have allowed us to identify regions of the sky where submillimeter galaxies (SMGs), powerful obscured starbursts at high-redshifts (z>1), cluster, and possibly mark the potential wells of accelerated galaxy-formation that will eventually form massive clusters. In this talk I will describe the evidence we have found for these overdense regions of massive galaxies, their structure and possible interpretation, as well as the follow-up observations we are carrying out with the LMT nowadays.

Thursday June 21, 2012
Prof. Françoise Combes
Observatoire de Paris, LERMA. France


I will review some recent results about the molecular content of galaxies and its dynamics, obtained from CO lines, dense tracers (HCN,HCO+), or the dust continuum emission. New data to constrain the conversion factor XCO will be discussed. The molecular surface density is essential to determine the star formation efficiency in galaxies, and the resolved Kennicutt-Schmidt law will be presented as a function of surface density and galaxy type. Large progress has been made on galaxy at moderate and high redshifts, allowing to interprete the star formation history and star formation efficiency as a function of gas content, or galaxy evolution. In massive galaxies, the gas fraction was higher in the past, and galaxy disks were more unstable and more turbulent. ALMA observations will allow the study of more normal galaxies at high z with higher spatial resolution and sensitivity.

Thursday March 24, 2011
Prof. Pierre Cox
IRAM, France


In recent years, major changes were done at the IRAM Plateau de Bure interferometer and 30-meter telescope, in particular in the areas of receivers and back-ends. These enhancements increased in significant ways both the sensitivity and the efficiency of both IRAM facilities. I will present results obtained on high-z (2 < 6.4) sub-millimeter galaxies and quasars that illustrate the progress that has been made, emphasizing recent follow-up observations of sources that were uncovered in the Herschel surveys. The talk will end with a presentation of the future projects that are currently under discussion at IRAM, including the NOrthern Extended Millimeter Array (NOEMA), as well as the prospects offered by ALMA.

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