scholarly journals Dust temperature in ALMA [C ii]-detected high-z galaxies

2021 ◽  
Vol 503 (4) ◽  
pp. 4878-4891
Author(s):  
L Sommovigo ◽  
A Ferrara ◽  
S Carniani ◽  
A Zanella ◽  
A Pallottini ◽  
...  
Keyword(s):  
Surface Density ◽  
Formation Rate ◽  
Empirical Relation ◽  
Density Ratio ◽  
Line Emission ◽  
Far Infrared ◽  
Single Observation ◽  
Dust Temperature ◽  
Analogous Relation ◽  
Single Data

ABSTRACT At redshift z > 5, the far-infrared (FIR) continuum spectra of main-sequence galaxies are sparsely sampled, often with a single data point. The dust temperature Td,SED, thus has to be assumed in the FIR continuum fitting. This introduces large uncertainties regarding the derived dust mass (Md), FIR luminosity, and obscured fraction of the star formation rate. These are crucial quantities to quantify the effect of dust obscuration in high-z galaxies. To overcome observation limitations, we introduce a new method that combines dust continuum information with the overlying [C $\scriptstyle \rm II$] 158 µm line emission. By breaking the Md–Td,SED degeneracy, with our method, we can reliably constrain the dust temperature with a single observation at 158 µm. This method can be applied to all Atacama Large Millimeter Array (ALMA) and NOEMA [C $\scriptstyle \rm II$] observations, and exploited in ALMA Large Programs such as ALPINE and REBELS targeting [C $\scriptstyle \rm II$] emitters at high-z. We also provide a physical interpretation of the empirical relation recently found between molecular gas mass and [C $\scriptstyle \rm II$] luminosity. We derive an analogous relation linking the total gas surface density and [C $\scriptstyle \rm II$] surface brightness. By combining the two, we predict the cosmic evolution of the surface density ratio $\Sigma _{\rm H_2} / \Sigma _{\rm gas}$. We find that $\Sigma _{\rm H_2} / \Sigma _{\rm gas}$ slowly increases with redshift, which is compatible with current observations at 0 < z < 4.

scholarly journals Gas, dust, and star formation in the positive AGN feedback candidate 4C 41.17 at z = 3.8

2020 ◽  
Vol 639 ◽  
pp. L13
Author(s):  
N. P. H. Nesvadba ◽  
G. V. Bicknell ◽  
D. Mukherjee ◽  
A. Y. Wagner
Keyword(s):  
Star Formation ◽  
Positive Feedback ◽  
Surface Density ◽  
High Redshift ◽  
Formation Rate ◽  
Line Emission ◽  
Far Infrared ◽  
Star Forming ◽  
Radio Jets ◽  
Narrow Ridge

We present new, spatially resolved [CI]1–0, [CI]2–1, CO(7–6), and dust continuum observations of 4C 41.17 at z = 3.8. This is one of the best-studied radio galaxies in this epoch and is arguably the best candidate of jet-triggered star formation at high redshift currently known in the literature. 4C 41.17 shows a narrow ridge of dust continuum extending over 15 kpc near the radio jet axis. Line emission is found within the galaxy in the region with signatures of positive feedback. Using the [CI]1–0 line as a molecular gas tracer, and multifrequency observations of the far-infrared dust heated by star formation, we find a total gas mass of 7.6 × 1010 M⊙, which is somewhat greater than that previously found from CO(4–3). The gas mass surface density of 103 M⊙ yr−1 pc−2 and the star formation rate surface density of 10 M⊙ yr−1 kpc−2 were derived over the 12 kpc × 8 kpc area, where signatures of positive feedback have previously been found. These densities are comparable to those in other populations of massive, dusty star-forming galaxies in this redshift range, suggesting that the jet does not currently enhance the efficiency with which stars form from the gas. This is consistent with expectations from simulations, whereby radio jets may facilitate the onset of star formation in galaxies without boosting its efficiency over longer timescales, in particular after the jet has broken out of the interstellar medium, as is the case in 4C 41.17.

scholarly journals Accurate dust temperature determination in a z = 7.13 galaxy

2021 ◽  
Author(s):  
Tom J L C Bakx ◽  
Laura Sommovigo ◽  
Stefano Carniani ◽  
Andrea Ferrara ◽  
Hollis B Akins ◽  
...  
Keyword(s):  
Formation Rate ◽  
Far Infrared ◽  
Spectral Energy ◽  
Ancillary Data ◽  
Star Forming ◽  
Dust Temperature ◽  
Density Fitting ◽  
Mass Estimate ◽  
Continuum Data ◽  
First Time

Abstract We report ALMA Band 9 continuum observations of the normal, dusty star-forming galaxy A1689-zD1 at z = 7.13, resulting in a ∼4.6 σ detection at 702 GHz. For the first time these observations probe the far-infrared (FIR) spectrum shortward of the emission peak of a galaxy in the Epoch of Reionization (EoR). Together with ancillary data from earlier works, we derive the dust temperature, Td, and mass, Md, of A1689-zD1 using both traditional modified blackbody spectral energy density fitting, and a new method that relies only on the [C ii] 158 μm line and underlying continuum data. The two methods give $T_{\rm d} = (42^{+13}_{-7}, 40^{+13}_{-7}$) K, and $M_{\rm d} = (1.7^{+1.3}_{-0.7}, 2.0^{+1.8}_{-1.0})\, \times {}\, 10^{7} \, M_{\odot }$. Band 9 observations improve the accuracy of the dust temperature (mass) estimate by ∼50 per cent (6 times). The derived temperatures confirm the reported increasing Td-redshift trend between z = 0 and 8; the dust mass is consistent with a supernova origin. Although A1689-zD1 is a normal UV-selected galaxy, our results, implying that ∼85 per cent of its star formation rate is obscured, underline the non-negligible effects of dust in EoR galaxies.

scholarly journals The ‘Red Radio Ring’: ionized and molecular gas in a starburst/active galactic nucleus at z ∼ 2.55

2019 ◽  
Vol 488 (2) ◽  
pp. 1489-1500 ◽  
Author(s):  
Kevin C Harrington ◽  
A Vishwas ◽  
A Weiß ◽  
B Magnelli ◽  
L Grassitelli ◽  
...  
Keyword(s):  
Fine Structure ◽  
Spectral Energy Distribution ◽  
Formation Rate ◽  
Line Emission ◽  
Far Infrared ◽  
Spectral Energy ◽  
Molecular Gas ◽  
H Ii Regions ◽  
Galaxy Assembly ◽  
Dust Attenuation

ABSTRACT We report the detection of the far-infrared (FIR) fine-structure line of singly ionized nitrogen, [N ii] 205 $\mu$m , within the peak epoch of galaxy assembly, from a strongly lensed galaxy, hereafter ‘The Red Radio Ring’; the RRR, at z = 2.55. We combine new observations of the ground-state and mid-J transitions of CO (Jup = 1, 5, 8), and the FIR spectral energy distribution (SED), to explore the multiphase interstellar medium (ISM) properties of the RRR. All line profiles suggest that the H ii regions, traced by [N ii] 205 $\mu$m , and the (diffuse and dense) molecular gas, traced by CO, are cospatial when averaged over kpc-sized regions. Using its mid-IR-to-millimetre (mm) SED, we derive a non-negligible dust attenuation of the [N ii] 205 $\mu$m line emission. Assuming a uniform dust screen approximation results a mean molecular gas column density >1024 cm−2, with a molecular gas-to-dust mass ratio of 100. It is clear that dust attenuation corrections should be accounted for when studying FIR fine-structure lines in such systems. The attenuation corrected ratio of $L_{\rm N\,{\small II}205} / L_{\rm IR(8\!-\!1000\, \mu m)} = 2.7 \times 10^{-4}$ is consistent with the dispersion of local and z > 4 SFGs. We find that the lower limit, [N ii] 205 $\mu$m -based star formation rate (SFR) is less than the IR-derived SFR by a factor of 4. Finally, the dust SED, CO line SED, and $L_{\rm N\,{\small II}205}$ line-to-IR luminosity ratio of the RRR is consistent with a starburst-powered ISM.

scholarly journals Exploring the Dust Content of Galactic Halos with Herschel*. III. NGC 891

2020 ◽  
Author(s):  
J H Yoon ◽  
C L Martin ◽  
S Veilleux ◽  
M Meléndez ◽  
T Mueller ◽  
...  
Keyword(s):  
Star Formation ◽  
Surface Density ◽  
Thermal Emission ◽  
Formation Rate ◽  
Critical Role ◽  
Cosmic Ray ◽  
Far Infrared ◽  
Starburst Galaxy ◽  
Galactic Halos ◽  
Infrared Observations

Abstract We present deep far-infrared observations of the nearby edge-on galaxy NGC 891 obtained with the Herschel Space Observatory and the Spitzer Space Telescope. The maps confirm the detection of thermal emission from the inner circumgalactic medium (halo) and spatially resolve a dusty superbubble and a dust spur (filament). The dust temperature of the halo component is lower than that of the disk but increases across a region of diameter ≈8.0 kpc extending at least 7.7 kpc vertically from one side of the disk, a region we call a superbubble because of its association with thermal X-ray emission and a minimum in the synchrotron scaleheight. This outflow is breaking through the thick disk and developing into a galactic wind, which is of particular interest because NGC 891 is not considered a starburst galaxy; the star formation rate surface density, 0.03M⊙ yr−1 kpc−2, and gas fraction, just $10\%$ in the inner disk, indicate the threshold for wind formation is lower than previous work has suggested. We conclude that the star formation surface density is sufficient for superbubble blowout into the halo, but the cosmic ray electrons may play a critical role in determining whether this outflow develops into a fountain or escapes from the gravitational potential. The high dust-to-gas ratio in the dust spur suggests the material was pulled out of NGC 891 through the collision of a minihalo with the disk of NGC 891. We conclude that NGC 891 offers an example of both feedback and satellite interactions transporting dust into the halo of a typical galaxy.

scholarly journals A proto-pseudobulge in ESO 320-G030 fed by a massive molecular inflow driven by a nuclear bar

2021 ◽  
Vol 645 ◽  
pp. A49 ◽  
Author(s):  
Eduardo González-Alfonso ◽  
Miguel Pereira-Santaella ◽  
Jaqueline Fischer ◽  
Santiago García-Burillo ◽  
Chentao Yang ◽  
...  
Keyword(s):  
Formation Rate ◽  
Far Infrared ◽  
Intermediate Stage ◽  
Spectroscopic Observations ◽  
Secular Evolution ◽  
Dust Temperature ◽  
The Galaxy ◽  
Continuum Data ◽  
Very High ◽  
Luminous Infrared Galaxy

Galaxies with nuclear bars are believed to efficiently drive gas inward, generating a nuclear starburst and possibly an active galactic nucleus. We confirm this scenario for the isolated, double-barred, luminous infrared galaxy ESO 320-G030 based on an analysis of Herschel and ALMA spectroscopic observations. Herschel/PACS and SPIRE observations of ESO 320-G030 show absorption or emission in 18 lines of H2O, which we combine with the ALMA H2O 423 − 330 448 GHz line (Eupper ∼ 400 K) and continuum images to study the physical properties of the nuclear region. Radiative transfer models indicate that three nuclear components are required to account for the multi-transition H2O and continuum data. An envelope, with radius R ∼ 130 − 150 pc, dust temperature Tdust ≈ 50 K, and NH2 ∼ 2 × 1023 cm−2, surrounds a nuclear disk with R ∼ 40 pc that is optically thick in the far-infrared (τ100 μm ∼ 1.5 − 3, NH2 ∼ 2 × 1024 cm−2). In addition, an extremely compact (R ∼ 12 pc), warm (≈100 K), and buried (τ100 μm >  5, NH2 ≳ 5 × 1024 cm−2) core component is required to account for the very high-lying H2O absorption lines. The three nuclear components account for 70% of the galaxy luminosity (SFR ∼ 16 − 18 M⊙ yr−1). The nucleus is fed by a molecular inflow observed in CO 2-1 with ALMA, which is associated with the nuclear bar. With decreasing radius (r = 450 − 225 pc), the mass inflow rate increases up to Ṁinf ∼ 20 Ṁ yr−1, which is similar to the nuclear star formation rate (SFR), indicating that the starburst is sustained by the inflow. At lower r, ∼100 − 150 pc, the inflow is best probed by the far-infrared OH ground-state doublets, with an estimated Ṁinf ∼ 30 Ṁ yr−1. The inferred short timescale of ∼20 Myr for nuclear gas replenishment indicates quick secular evolution, and indicates that we are witnessing an intermediate stage (< 100 Myr) proto-pseudobulge fed by a massive inflow that is driven by a strong nuclear bar. We also apply the H2O model to the Herschel far-infrared spectroscopic observations of H218O, OH, 18OH, OH+, H2O+, H3O+, NH, NH2, NH3, CH, CH+, 13CH+, HF, SH, and C3, and we estimate their abundances.

scholarly journals sígame v3: Gas Fragmentation in Postprocessing of Cosmological Simulations for More Accurate Infrared Line Emission Modeling

2021 ◽  
Vol 922 (1) ◽  
pp. 88
Author(s):  
Karen Pardos Olsen ◽  
Blakesley Burkhart ◽  
Mordecai-Mark Mac Low ◽  
Robin G. Treß ◽  
Thomas R. Greve ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Probability Distribution Function ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Sample Selection ◽  
Line Emission ◽  
Far Infrared ◽  
Emission Lines ◽  
Nearby Galaxies ◽  
A New Technique

Abstract We present an update to the framework called Simulator of Galaxy Millimeter/submillimeter Emission (sígame). sígame derives line emission in the far-infrared (FIR) for galaxies in particle-based cosmological hydrodynamics simulations by applying radiative transfer and physics recipes via a postprocessing step after completion of the simulation. In this version, a new technique is developed to model higher gas densities by parameterizing the probability distribution function (PDF) of the gas density in higher-resolution simulations run with the pseudo-Lagrangian, Voronoi mesh code arepo. The parameterized PDFs are used as a look-up table, and reach higher densities than in previous work. sígame v3 is tested on redshift z = 0 galaxies drawn from the simba cosmological simulation for eight FIR emission lines tracing vastly different phases of the interstellar medium. This version of sígame includes dust radiative transfer with Skirt and high-resolution photoionization models with Cloudy, the latter sampled according to the density PDF of the arepo simulations to augment the densities in the cosmological simulation. The quartile distributions of the predicted line luminosities overlap with the observed range for nearby galaxies of similar star formation rate (SFR) for all but two emission lines: [O i]63 and CO(3–2), which are overestimated by median factors of 1.3 and 1.0 dex, respectively, compared to the observed line–SFR relation of mixed-type galaxies. We attribute the remaining disagreement with observations to the lack of precise attenuation of the interstellar light on sub-grid scales (≲200 pc) and differences in sample selection.

scholarly journals The Resolved Kennicutt-Schmidt Law in Nearby Galaxies

2012 ◽  
Vol 8 (S292) ◽  
pp. 335-335
Author(s):  
R. Momose ◽  
J. Koda ◽  
R. C. Kennicutt ◽  
F. Egusa ◽  
S. K. Okumura ◽  
...  
Keyword(s):  
Star Formation ◽  
Power Law ◽  
Surface Density ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Line Emission ◽  
Molecular Gas ◽  
Disk Galaxies ◽  
Nearby Galaxies ◽  
Power Law Index

AbstractThe Kennicutt-Schmidt law (Schmidt 1959; Kennicutt 1998, hereafter K-S law) is a power law correlation between area averaged star formation rate (ΣSFR) and gas surface density (Σgas). Despite its importance, the physics that underlie this correlation has remained unclear. The power law index, N, is a prime discriminator of the mechanisms that regulate star formation and form the K-S law (e.g. Leroy et al. 2008; Tan 2010). We present a study of the resolved K-S law for 10 nearby disk galaxies using our new CO(1-0) data at 750 and 500 pc resolutions. The CO(1-0) line emission is established as a tracer of the molecular gas column density, and results in a super-linear correlation (N = 1.3 and 1.8). We discuss the cause of the discrepancy between previous studies, and the mechanism of star formation indicated from our new results.

scholarly journals The HASHTAG project I. A survey of CO(3–2) emission from the star forming disc of M31

2019 ◽  
Vol 492 (1) ◽  
pp. 195-209 ◽  
Author(s):  
Zongnan Li ◽  
Zhiyuan Li ◽  
Matthew W L Smith ◽  
Christine D Wilson ◽  
Yu Gao ◽  
...  
Keyword(s):  
Star Formation ◽  
Surface Density ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Rank Correlation ◽  
Star Forming ◽  
Spearman’S Rank Correlation ◽  
Dust Temperature ◽  
Spearman’S Rank Correlation Coefficient ◽  
Nuclear Ring

ABSTRACT We present a CO(3–2) survey of selected regions in the M31 disc as part of the JCMT large programme, HARP and SCUBA-2 High-Resolution Terahertz Andromeda Galaxy Survey (HASHTAG). The 12 CO(3–2) fields in this survey cover a total area of 60 arcmin2, spanning a deprojected radial range of 2–14 kpc across the M31 disc. Combining these observations with existing IRAM 30 m CO(1–0) observations and JCMT CO(3–2) maps of the nuclear region of M31, as well as dust temperature and star formation rate surface density maps, we are able to explore the radial distribution of the CO(3–2)/CO(1–0) integrated intensity ratio (R31) and its relationship with dust temperature and star formation. We find that the value of R31 between 2 and 9 kpc galactocentric radius is 0.14, significantly lower than what is seen in the nuclear ring at 1 kpc (R31 ∼ 0.8), only to rise again to 0.27 for the fields centred on the 10 kpc star forming ring. We also found that R31 is positively correlated with dust temperature, with Spearman’s rank correlation coefficient ρ = 0.55. The correlation between star formation rate surface density and CO(3–2) intensity is much stronger than with CO(1–0), with ρ = 0.54 compared to –0.05, suggesting that the CO(3–2) line traces warmer and denser star forming gas better. We also find that R31 correlates well with star formation rate surface density, with ρ = 0.69.

Census of and Lyα, [Oiii]5007, Hα, and [Ciii]158 μm line emission wiht ∼1000 galaxies at z = 4.9 – 7.0 revealed with Subaru/HSC, Spitzer, and ALMA

2019 ◽  
Vol 15 (S341) ◽  
pp. 206-210
Author(s):  
Yuichi Harikane
Keyword(s):  
Rest Frame ◽  
Formation Rate ◽  
Line Emission ◽  
Flux Ratio ◽  
Optical Emission ◽  
Far Infrared ◽  
Infrared Emission ◽  
Emission Lines ◽  
The Galaxy ◽  
Turn Over

AbstractWe investigate rest-frame UV to far-infrared emission lines and SEDs from 1124 galaxies at z = 4.9 – 7.0. Our sample is composed of 1092 Lyα emitters (LAEs) at z = 4.9–7.0 identified by Subaru/Hyper Suprime-Cam (HSC) narrowband surveys and 34 galaxies at z = 5.148–7.508 with deep [Cii]158μm ALMA data. The SEDs clearly show flux excesses in the Spitzer/IRAC 3.6 and 4.5μm bands, suggesting strong rest-frame optical emission lines of [Oiii] and/or Hα. We model the galaxy SEDs with a flexible code combining stellar population and photoionization models (BEAGLE; Chevallard & Charlot 2016), and investigate relations between the emission lines of Lyα, [Oiii], Hα, and [CII]. We find 1) a positive correlation between the rest-frame Hα equivalent width (EW) and the Lyα, EW, ${\EW {^0_Ly\alpha}} $, 2) an interesting turn-over trend that the [Oiii]/Hα flux ratio increases in ${\EW {^0_Ly\alpha}} $ ≃ 0–30 Å, and then decreases out to ${\EW {^0_Ly\alpha}} $ ≃ 130 Å, and 3) a > 99% anti-correlation between a [Cii] luminosity to star-formation rate ratio L[Cii]/SFR) and ${\EW {^0_Ly\alpha}} $. Modeling with BEAGLE also suggests that a simple anticorrelation between ${\EW {^0_Ly\alpha}} $ and metallicity explains self-consistently all of the relations of Lyα, Hα, [Oiii]/Hα, and [Cii] in our study, indicative of detections of very metal-poor (∼0.03Z⊙) galaxies with ${\EW {^0_Ly\alpha}} $ ∼200 Å.

scholarly journals Mapping large-scale-structure evolution over cosmic times

2021 ◽  
Author(s):  
Marta B. Silva ◽  
Ely D. Kovetz ◽  
Garrett K. Keating ◽  
Azadeh Moradinezhad Dizgah ◽  
Matthieu Bethermin ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Large Scale ◽  
High Redshift ◽  
Formation Rate ◽  
Far Infrared ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Structure Evolution ◽  
Intensity Mapping ◽  
Wide Range

AbstractThis paper outlines the science case for line-intensity mapping with a space-borne instrument targeting the sub-millimeter (microwaves) to the far-infrared (FIR) wavelength range. Our goal is to observe and characterize the large-scale structure in the Universe from present times to the high redshift Epoch of Reionization. This is essential to constrain the cosmology of our Universe and form a better understanding of various mechanisms that drive galaxy formation and evolution. The proposed frequency range would make it possible to probe important metal cooling lines such as [CII] up to very high redshift as well as a large number of rotational lines of the CO molecule. These can be used to trace molecular gas and dust evolution and constrain the buildup in both the cosmic star formation rate density and the cosmic infrared background (CIB). Moreover, surveys at the highest frequencies will detect FIR lines which are used as diagnostics of galaxies and AGN. Tomography of these lines over a wide redshift range will enable invaluable measurements of the cosmic expansion history at epochs inaccessible to other methods, competitive constraints on the parameters of the standard model of cosmology, and numerous tests of dark matter, dark energy, modified gravity and inflation. To reach these goals, large-scale structure must be mapped over a wide range in frequency to trace its time evolution and the surveyed area needs to be very large to beat cosmic variance. Only a space-borne mission can properly meet these requirements.

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