scholarly journals Future prospects in observational galaxy evolution: towards increased resolution

2012 ◽  
Vol 8 (S295) ◽  
pp. 368-375
Author(s):  
Karl Glazebrook
Keyword(s):  
Galaxy Evolution ◽  
High Redshift ◽  
Personal Perspective ◽  
Molecular Gas ◽  
Future Prospects ◽  
Kinematic Data ◽  
Near Ir ◽  
Large Numbers ◽  
Ir Spectroscopic ◽  
Integral Field

AbstractFuture prospects in observational galaxy evolution are reviewed from a personal perspective. New insights will especially come from high-redshift integral field kinematic data and similar low-redshift observations in very large and definitive surveys. We will start to systematically probe the mass structures of galaxies and their haloes via lensing from new imaging surveys and upcoming near-IR spectroscopic surveys will finally obtain large numbers of rest frame optical spectra at high-redshift routinely. ALMA will be an important new ingredient, spatially resolving the molecular gas fuelling the high star-formation rates seen in the early Universe.

Cold gas studies of a z = 2.5 protocluster

2020 ◽  
Vol 15 (S359) ◽  
pp. 136-140
Author(s):  
Minju M. Lee ◽  
Ichi Tanaka ◽  
Rohei Kawabe
Keyword(s):  
Galaxy Evolution ◽  
High Redshift ◽  
Kinematic Model ◽  
Molecular Gas ◽  
General View ◽  
Massive Galaxies ◽  
Star Forming ◽  
Gas Kinematics ◽  
Narrow Band Filter ◽  
Stellar Masses

AbstractWe present studies of a protocluster at z =2.5, an overdense region found close to a radio galaxy, 4C 23.56, using ALMA. We observed 1.1 mm continuum, two CO lines (CO (4–3) and CO (3–2)) and the lower atomic carbon line transition ([CI](3P1-3P0)) at a few kpc (0″.3-0″.9) resolution. The primary targets are 25 star-forming galaxies selected as Hα emitters (HAEs) that are identified with a narrow band filter. These are massive galaxies with stellar masses of > 1010Mʘ that are mostly on the galaxy main sequence at z =2.5. We measure the molecular gas mass from the independent gas tracers of 1.1 mm, CO (3–2) and [CI], and investigate the gas kinematics of galaxies from CO (4–3). Molecular gas masses from the different measurements are consistent with each other for detection, with a gas fraction (fgas = Mgas/(Mgas+ Mstar)) of ≃ 0.5 on average but with a caveat. On the other hand, the CO line widths of the protocluster galaxies are typically broader by ˜50% compared to field galaxies, which can be attributed to more frequent, unresolved gas-rich mergers and/or smaller sizes than field galaxies, supported by our high-resolution images and a kinematic model fit of one of the galaxies. We discuss the expected scenario of galaxy evolution in protoclusters at high redshift but future large surveys are needed to get a more general view.

scholarly journals Stellar populations in the highest redshift galaxies

2015 ◽  
Vol 11 (A29B) ◽  
pp. 197-198
Author(s):  
Andrew J. Bunker
Keyword(s):  
Galaxy Evolution ◽  
High Redshift ◽  
Stellar Populations ◽  
Mass Function ◽  
Initial Mass Function ◽  
Star Forming ◽  
Near Ir ◽  
James Webb Space Telescope ◽  
Large Telescopes ◽  
The Universe

AbstractI discuss stellar populations in galaxies at high redshift (z > 6), in particular the blue rest-frame UV colours which have been detected in recent years through near-IR imaging with HST. These spectral slopes of β < −2 are much more blue than star-forming galaxies at lower redshift, and may suggest less dust obscuration, lower metallicity or perhaps a different initial mass function. I describe current work on the luminosity function of high redshift star- forming galaxies, the evolution of the fraction of strong Lyman-α emitters in this population, and the contribution of the ionizing photon budget from such galaxies towards the reionization of the Universe. I also describe constraints placed by Spitzer/IRAC on stellar populations in galaxies within the first billion years, and look towards future developments in spectroscopy with Extremely Large Telescopes and the James Webb Space Telescope, including the JWST/NIRSpec GTO programme on galaxy evolution at high redshift.

scholarly journals Widespread star formation inside galactic outflows

2019 ◽  
Vol 485 (3) ◽  
pp. 3409-3429 ◽  
Author(s):  
R Gallagher ◽  
R Maiolino ◽  
F Belfiore ◽  
N Drory ◽  
R Riffel ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Scaling Relations ◽  
Molecular Gas ◽  
Distant Galaxies ◽  
Major Mode ◽  
Galactic Outflows ◽  
The Universe ◽  
Integral Field

Abstract Several models have predicted that stars could form inside galactic outflows and that this would be a new major mode of galaxy evolution. Observations of galactic outflows have revealed that they host large amounts of dense and clumpy molecular gas, which provide conditions suitable for star formation. We have investigated the properties of the outflows in a large sample of galaxies by exploiting the integral field spectroscopic data of the large MaNGA-SDSS4 galaxy survey. We find evidence for prominent star formation occurring inside at least 30 per cent of the galactic outflows in our sample, whilst signs of star formation are seen in up to half of the outflows. We also show that even if star formation is prominent inside many other galactic outflows, this may have not been revealed as the diagnostics are easily dominated by the presence of even faint active galactic nucleus and shocks. If very massive outflows typical of distant galaxies and quasars follow the same scaling relations observed locally, then the star formation inside high-z outflows can be up to several 100 $\rm M_{\odot }~yr^{-1}$ and could contribute substantially to the early formation of the spheroidal component of galaxies. Star formation in outflows can also potentially contribute to establishing the scaling relations between black holes and their host spheroids. Moreover, supernovae exploding on large orbits can chemically enrich in situ and heat the circumgalactic and intergalactic medium. Finally, young stars ejected on large orbits may also contribute to the reionization of the Universe.

scholarly journals A molecular scan in the Hubble Deep Field North

2014 ◽  
Vol 10 (S309) ◽  
pp. 265-268
Author(s):  
Roberto Decarli ◽  
Fabian Walter ◽  
Chris Carilli ◽  
Dominik Riechers
Keyword(s):  
Galaxy Evolution ◽  
High Redshift ◽  
Broad Band ◽  
Gas Content ◽  
Continuum Emission ◽  
Molecular Gas ◽  
Normal Galaxies ◽  
Hubble Deep Field ◽  
The Universe ◽  
Selection Of

AbstractOur understanding of galaxy evolution has traditionally been driven by pre-selection of galaxies based on their broad-band continuum emission. This approach is potentially biased, in particular against gas-rich systems at high-redshift which may be dust-obscured. To overcome this limitation, we have recently concluded a blind CO survey at 3mm in a region of the Hubble Deep Field North using the IRAM Plateau de Bure Interferometer. Our study resulted in 1) the discovery of the redshift of the bright SMG HDF850.1 (z = 5.183); 2) the discovery of a bright line identified as CO(2-1) arising from a BzK galaxy at z = 1.785, and of other 6 CO lines associated with various galaxies in the field; 3) the detection of a few lines (presumably CO(3-2) at z ∼ 2) with no optical/NIR/MIR counterparts. These observational results allowed us to expand the parameter space of galaxy properties probed so far in high-z molecular gas studies. Most importantly, we could set first direct constraints on the cosmic evolution of the molecular gas content of the universe. The present study represents a first, fundamental step towards an unbiased census of molecular gas in ‘normal’ galaxies at high-z, a crucial goal of extragalactic astronomy in the ALMA era.

Infrared Surveys from Antarctica

1996 ◽  
Vol 13 (1) ◽  
pp. 7-9 ◽  
Author(s):  
Jeremy Bailey
Keyword(s):  
Galaxy Evolution ◽  
Molecular Hydrogen ◽  
High Redshift ◽  
Brown Dwarfs ◽  
Emission Lines ◽  
Star Forming ◽  
Hydrogen Emission ◽  
Near Ir ◽  
Infrared Surveys ◽  
Galactic Sources

AbstractThe very low background observed from Antarctica in a window from about 2·25 to 2·45 μm can be exploited as a way of making deep near-IR surveys over wide areas of sky. Imaging surveys using the entire window can cover large areas of sky to limits of around K = 20, and can be used to study galaxy evolution and to search for high-redshift quasars, dust-obscured quasars and brown dwarfs. It is also possible to make spectroscopic surveys in this window. The window includes molecular hydrogen emission and CO absorption in galactic sources, and can also be used to search for emission lines such as Hα in high-redshift star-forming galaxies.

Revealing AGN, young and old stellar populations in HzRGs with PEGASE.3

2013 ◽  
Vol 9 (S304) ◽  
pp. 307-310
Author(s):  
Guillaume Drouart ◽  
Carlos De Breuck ◽  
Joël Vernet ◽  
Brigitte Rocca Volmerange ◽  
Nicholas Seymour
Keyword(s):  
Galaxy Evolution ◽  
Stellar Population ◽  
Radio Galaxy ◽  
High Redshift ◽  
Radio Galaxies ◽  
Host Galaxies ◽  
Continuous Coverage ◽  
Near Ir ◽  
The Relationship ◽  
Very High

AbstractThe HeRGÉ (Herschel Radio Galaxy Evolution) project consists of a sample of 70 radio galaxies in the range 1 < z < 5.2. They benefit from continuous coverage from 3 to 870μm with Spitzer, Herschel and sub-mm ground-based instruments (SCUBA, LABOCA). As a calorimeter, IR is an excellent proxy to estimate the contribution of both AGN and starburst, making of radio galaxies perfect candidates to provide new insights into the relationship between AGN and their host galaxies. The IR SED fitting with empirical templates reveals that radio galaxies are luminous and that their black holes and their host galaxies are not growing simultaneously. Extending the SED to optical/near-IR on a subsample of 12 radio galaxies spanning 1 < z < 4 reveal the necessity of three components to reproduce the observations. Making use of the evolutionary code PEGASE.3 and an AGN torus model, we are able to estimate parameters from the AGN torus, the evolved stellar population and the starburst (SB). They reveal that radio galaxies are massive, evolved, forming the bulk of their mass at very high redshift in a short timescale, but experience episodic, strong SB events, often associated with an AGN activity.

scholarly journals Space Project for Astrophysical and Cosmological Exploration (SPACE), an ESA stand-alone mission and a possible contribution to the Origins Space Telescope

2021 ◽  
Author(s):  
Denis Burgarella ◽  
Andrew Bunker ◽  
Rychard Bouwens ◽  
Laurent Pagani ◽  
Jose Afonso ◽  
...  
Keyword(s):  
Black Holes ◽  
Galaxy Evolution ◽  
High Redshift ◽  
Cosmic Time ◽  
Wide Field ◽  
Unique Region ◽  
Space Telescope ◽  
Near Ir ◽  
Space Project ◽  
First Galaxies

AbstractWe propose a new mission called Space Project for Astrophysical and Cosmological Exploration (SPACE) as part of the ESA long term planning Voyage 2050 programme. SPACE will study galaxy evolution at the earliest times, with the key goals of charting the formation of the heavy elements, measuring the evolution of the galaxy luminosity function, tracing the build-up of stellar mass in galaxies over cosmic time, and finding the first super-massive black holes (SMBHs) to form. The mission will exploit a unique region of the parameter space, between the narrow ultra-deep surveys with HST and JWST, and shallow wide-field surveys such as the Roman Space Telescope and EUCLID, and should yield by far the largest sample of any current or planned mission of very high redshift galaxies at z > 10 which are sufficiently bright for detailed follow-up spectroscopy. Crucially, we propose a wide-field spectroscopic near-IR + mid-IR capability which will greatly enhance our understanding of the first galaxies by detecting and identifying a statistical sample of the first galaxies and the first supermassive black holes, and to chart the metal enrichment history of galaxies in the early Universe – potentially finding signatures of the very first stars to form from metal-free primordial gas. The wide-field and wavelength range of SPACE will also provide us a unique opportunity to study star formation by performing a wide survey of the Milky Way in the near-IR + mid-IR. This science project can be enabled either by a stand-alone ESA-led M mission or by an instrument for an L mission (with ESA and/or NASA, JAXA and other international space agencies) with a wide-field (sub-)millimetre capability at λ > 500 μm.

scholarly journals Detecting CO at High Redshift

1996 ◽  
Vol 171 ◽  
pp. 151-154
Author(s):  
Linda J. Tacconi
Keyword(s):  
Galaxy Evolution ◽  
Galaxy Formation ◽  
Driving Forces ◽  
High Redshift ◽  
Line Emission ◽  
Host Galaxy ◽  
Molecular Gas ◽  
Ultraluminous Infrared Galaxies ◽  
Star Formation In Galaxies ◽  
Cold Dust

Searches for molecular line emission from high redshift galaxies have become one of the recent highlights in millimeter astronomy, largely because detection of this emission enables one to study the potential for star formation in galaxies at epochs close to galaxy formation. Such information is crucial to models of galaxy evolution. Thus far, most of the searches have been to try to detect any of the rotational lines of CO, although many authors have also inferred the presence of molecular gas through detections of cold dust in the submillimeter region of the spectrum. In addition to providing information about the physical properties of the molecular gas in distant galaxies (when more than one transition or isotope is detected), the CO lines can be used to place stringent constrints on the dynamical masses of these systems. Moreover, since millimeter data has spectral resolutions of typically a few tens of km/s, one can pin down the redshift of the host galaxy with extremely high precision. One of the driving forces in most of the searches for CO emission at high redshift is the fact that molecular gas is known to be an important constituent in the low redshift counterparts to the types of objects that one expects to find at high redshifts, the Ultraluminous Infrared Galaxies (ULIRGs), (e.g. Mirabel and Sanders 1985; Sanders et al. 1986), powerful radio galaxies (e.g. Mazzarella et al. 1993), and nearby quasars (e.g. Barvainis et al. 1989), for example.

scholarly journals Nature and physical properties of gas-mass selected galaxies using integral field spectroscopy

2019 ◽  
Vol 15 (S352) ◽  
pp. 326-330
Author(s):  
Leindert A. Boogaard
Keyword(s):  
Physical Properties ◽  
High Redshift ◽  
Formation Rate ◽  
Cosmic Time ◽  
Gas Content ◽  
Molecular Gas ◽  
Integral Field Spectroscopy ◽  
Field Spectroscopy ◽  
Integral Field ◽  
Cold Gas

AbstractMapping the molecular gas content of the universe is key to our understanding of the build-up of galaxies over cosmic time. Spectral line scans in deep fields, such as the Hubble Ultra Deep Field (HUDF), provide a unique view on the cold gas content out to high redshift. By conducting ‘spectroscopy-of-everything’, these flux-limited observations are sensitive to the molecular gas in galaxies without preselection, revealing the cold gas content of galaxies that would not be selected in traditional studies.In order to capitalize on the molecular gas observations, knowledge about the physical conditions of the galaxies detected in molecular gas, such as their interstellar medium conditions, is key. Fortunately, deep surveys with integral-field spectrographs are providing an unprecedented view of the galaxy population, providing redshifts and measurements of restframe UV/optical lines for thousands of galaxies.We present the results from the synergy between the ALMA Spectroscopic Survey of the HUDF (ASPECS), with deep integral field spectroscopy from the MUSE HUDF survey and multi-wavelength data. We discuss the nature of the galaxies detected in molecular gas without preselection and their physical properties, such as star formation rate and metallicity. We show how the combination of ALMA and MUSE integral field spectroscopy can constrain the physical properties in galaxies located around the main sequence during the peak of galaxy formation.

NIR–IFU observations of the merger remnant NGC 34

2019 ◽  
Vol 15 (S359) ◽  
pp. 355-356
Author(s):  
Juliana C. Motter ◽  
Rogério Riffel ◽  
Tiago V. Ricci ◽  
Natacha Z. Dametto ◽  
Luis G. Dahmer-Hahn ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
Adaptive Optics ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Molecular Gas ◽  
The Galaxy ◽  
Open Issue ◽  
Nuclear Regions ◽  
Disc Galaxies ◽  
Integral Field

AbstractUnderstanding the interplay between the phenomena of active galactic nuclei (AGN) and starbursts remains an open issue in studies of galaxy evolution. The galaxy NGC 34 is the remnant of the merger of two former gas-rich disc galaxies and it also hosts a strong nuclear starburst. In this work, we map the ionized and molecular gas present in the nuclear regions of the galaxy NGC 34 using adaptive optics (AO) assisted near infrared (NIR) integral field unity (IFU) observations. Our main goals are to better constrain the energy source of this object and to use NGC 34 as a laboratory to probe the AGN-starburst connection in the context of galaxy evolution and AGN feeding and feedback processes.

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