Stellar clusters in the inner Galaxy and their correlation with cold dust emission

Aims. We use multi-band observations by the Herschel Space Observatory to study the dust emission properties of the nearby spiral galaxy NGC 300. We compile a first catalogue of the population of giant dust clouds (GDCs) in NGC 300, including temperature and mass estimates, and give an estimate of the total dust mass of the galaxy. Methods. We carried out source detection with the multiwavelength source extraction algorithm getsources. We calculated physical properties, including mass and temperature, of the GDCs from five-band Herschel PACS and SPIRE observations from 100 to 500 μm; the final size and mass estimates are based on the observations at 250 μm that have an effective spatial resolution of ~170 pc. We correlated our final catalogue of GDCs to pre-existing catalogues of HII regions to infer the number of GDCs associated with high-mass star formation and determined the Hα emission of the GDCs. Results. Our final catalogue of GDCs includes 146 sources, 90 of which are associated with known HII regions. We find that the dust masses of the GDCs are completely dominated by the cold dust component and range from ~1.1 × 103 to 1.4 × 104 M⊙. The GDCs have effective temperatures of ~13–23 K and show a distinct cold dust effective temperature gradient from the centre towards the outer parts of the stellar disk. We find that the population of GDCs in our catalogue constitutes ~16% of the total dust mass of NGC 300, which we estimate to be about 5.4 × 106 M⊙. At least about 87% of our GDCs have a high enough average dust mass surface density to provide sufficient shielding to harbour molecular clouds. We compare our results to previous pointed molecular gas observations in NGC 300 and results from other nearby galaxies and also conclude that it is very likely that most of our GDCs are associated with complexes of giant molecular clouds.

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Probing the Cold Dust Emission in the AB Aur Disk: A Dust Trap in a Decaying Vortex?

The Astrophysical Journal ◽

10.3847/2041-8213/aa8558 ◽

2017 ◽

Vol 846 (1) ◽

pp. L3 ◽

Cited By ~ 15

Author(s):

Asunción Fuente ◽

Clément Baruteau ◽

Roberto Neri ◽

Andrés Carmona ◽

Marcelino Agúndez ◽

...

Keyword(s):

Dust Emission ◽

Dust Trap ◽

Cold Dust

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Dust emission profiles of DustPedia galaxies

Astronomy and Astrophysics ◽

10.1051/0004-6361/201833932 ◽

2019 ◽

Vol 622 ◽

pp. A132 ◽

Cited By ~ 11

Author(s):

A. V. Mosenkov ◽

M. Baes ◽

S. Bianchi ◽

V. Casasola ◽

L. P. Cassarà ◽

...

Keyword(s):

Large Scale ◽

Near Infrared ◽

Spiral Galaxies ◽

Radial Profile ◽

Dust Emission ◽

Outer Part ◽

Average Value ◽

Inner Region ◽

Cold Dust ◽

Optical Radius

Most radiative transfer models assume that dust in spiral galaxies is distributed exponentially. In this paper our goal is to verify this assumption by analysing the two-dimensional large-scale distribution of dust in galaxies from the DustPedia sample. For this purpose, we have made use of Herschel imaging in five bands, from 100 to 500 μm, in which the cold dust constituent is primarily traced and makes up the bulk of the dust mass in spiral galaxies. For a subsample of 320 disc galaxies, we successfully performed a simultaneous fitting with a single Sérsic model of the Herschel images in all five bands using the multi-band modelling code GALFITM. We report that the Sérsic index n, which characterises the shape of the Sérsic profile, lies systematically below 1 in all Herschel bands and is almost constant with wavelength. The average value at 250 μm is 0.67 ± 0.37 (187 galaxies are fitted with n250 ≤ 0.75, 87 galaxies have 0.75 < n250 ≤ 1.25, and 46 – with n250 > 1.25). Most observed profiles exhibit a depletion in the inner region (at r < 0.3−0.4 of the optical radius r25) and are more or less exponential in the outer part. We also find breaks in the dust emission profiles at longer distances (0.5−0.6) r25 which are associated with the breaks in the optical and near-infrared. We assumed that the observed deficit of dust emission in the inner galaxy region is related to the depression in the radial profile of the HI surface density in the same region because the atomic gas reaches high enough surface densities there to be transformed into molecular gas. If a galaxy has a triggered star formation in the inner region (for example, because of a strong bar instability, which transfers the gas inwards to the centre, or a pseudobulge formation), no depletion or even an excess of dust emission in the centre is observed.

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Dust-enshrouded AGNs Can Dominate Host-galaxy-scale Cold Dust Emission

The Astrophysical Journal ◽

10.3847/1538-4357/ac185f ◽

2021 ◽

Vol 921 (1) ◽

pp. 55

Author(s):

Jed McKinney ◽

Christopher C. Hayward ◽

Lee J. Rosenthal ◽

Juan Rafael Martínez-Galarza ◽

Alexandra Pope ◽

...

Keyword(s):

Dust Emission ◽

Host Galaxy ◽

Cold Dust

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Synthetic observations of dust emission and polarisation of Galactic cold clumps

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935882 ◽

2019 ◽

Vol 629 ◽

pp. A63 ◽

Cited By ~ 2

Author(s):

Mika Juvela ◽

Paolo Padoan ◽

Isabelle Ristorcelli ◽

Veli-Matti Pelkonen

Keyword(s):

Magnetic Field ◽

Surface Brightness ◽

Dust Emission ◽

Dense Medium ◽

Star Forming ◽

Aspect Ratios ◽

Field Geometry ◽

The Mean ◽

Cold Dust ◽

Synthetic Catalogue

Context. The Planck Catalogue of Galactic Cold Clumps (PGCC) contains over 13 000 sources that are detected based on their cold dust signature. They are believed to consist of a mixture of quiescent, pre-stellar, and already star-forming objects within molecular clouds. Aims. We extracted PGCC-type objects from cloud simulations and examined their physical and polarisation properties. The comparison with the PGCC catalogue helps to characterise the properties of this large sample of Galactic objects and, conversely, provides valuable tests for numerical simulations of large volumes of the interstellar medium and the evolution towards pre-stellar cores. Methods. We used several magnetohydrodynamical simulation snapshots to define the density field of our model clouds. Sub-millimetre images of the surface brightness and polarised signal were obtained with radiative transfer calculations. We examined the statistics of synthetic cold clump catalogues extracted with methods similar to the PGCC. We also examined the variations of the polarisation fraction p in the clumps. Results. The clump sizes, aspect ratios, and temperatures in the synthetic catalogue are similar to the PGCC. The fluxes and column densities of synthetic clumps are smaller by a factor of a few. Rather than with an increased dust opacity, this could be explained by increasing the average column density of the model by a factor of two to three, close to N(H2) = 1022 cm−2. When the line of sight is parallel to the mean magnetic field, the polarisation fraction tends to increase towards the clump centres, which is contrary to observations. When the field is perpendicular, the polarisation fraction tends to decrease towards the clumps, but the drop in p is small (e.g. from p ~8% to p ~7%). Conclusions. Magnetic field geometry reduces the polarisation fraction in the simulated clumps by only Δp ~1% on average. The larger drop seen towards the actual PGCC clumps therefore suggests some loss of grain alignment in the dense medium, such as predicted by the radiative torque mechanism. The statistical study is not able to quantify dust opacity changes at the scale of the PGCC clumps.

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Cold dust emission from X-ray AGN in the SCUBA-2 Cosmology Legacy Survey: dependence on luminosity, obscuration and AGN activity

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stv1881 ◽

2015 ◽

Vol 454 (1) ◽

pp. 419-438 ◽

Cited By ~ 11

Author(s):

Manda Banerji ◽

R. G. McMahon ◽

C. J. Willott ◽

J. E. Geach ◽

C. M. Harrison ◽

...

Keyword(s):

Dust Emission ◽

X Ray ◽

Cold Dust

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Cold dust and stellar emissions in dust-rich galaxies observed with ALMA: a challenge for SED-fitting techniques

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936643 ◽

2019 ◽

Vol 632 ◽

pp. A79 ◽

Cited By ~ 5

Author(s):

V. Buat ◽

L. Ciesla ◽

M. Boquien ◽

K. Małek ◽

D. Burgarella

Keyword(s):

Star Formation ◽

Rest Frame ◽

Near Infrared ◽

Formation Rate ◽

Dust Emission ◽

Spectral Energy ◽

Physical Parameters ◽

Modeling Tools ◽

Attenuation Law ◽

Cold Dust

Context. Over the past few years the Atacama Large Millimeter Array (ALMA) has detected dust-rich galaxies whose cold dust emission is spatially disconnected from the ultraviolet (UV) rest-frame emission. This represents a challenge for modeling their spectral energy distributions (SED) with codes based on an energy budget between the stellar and dust components. This could potentially weaken the solidity of the physical parameters measured with these modeling tools. Aims. We want to verify the validity of energy balance modeling on a sample of galaxies observed from the UV to the sub-millimeter rest frame with ALMA and decipher what information can be reliably retrieved from the analysis of the full SED and from subsets of wavelengths. Methods. We select 17 sources at z ≃ 2 in the Hubble Ultra-Deep Field (HUDF) and in the GOODS-South field detected with ALMA and Herschel and for which UV to near-infrared rest-frame ancillary data are available. We fit the data with CIGALE exploring different configurations for dust attenuation and star formation histories, considering either the full dataset or one that is reduced to the stellar and dust emission. We compare estimates of the dust luminosities, star formation rates, and stellar masses. Results. The fit of the stellar continuum alone with the starburst attenuation law can only reproduce up to 50% of the total dust luminosity observed by Herschel and ALMA. This deficit is found to be marginally consistent with similar quantities estimated in the COSMOS field and is found to increase with the specific star formation rate. The combined stellar and dust SEDs are well fitted when different attenuation laws are introduced. Shallow attenuation curves are needed for the galaxies whose cold dust distribution is very compact compared to starlight. The stellar mass estimates are affected by the choice of the attenuation law. The star formation rates are robustly estimated as long as dust luminosities are available. The large majority of the galaxies are above the average main sequence of star forming galaxies and one source is a strong starburst.

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Galactic cold cores

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314012241 ◽

2012 ◽

Vol 10 (H16) ◽

pp. 577-578

Author(s):

M. Juvela ◽

Keyword(s):

Star Formation ◽

Dust Emission ◽

Far Infrared ◽

Point Sources ◽

Interstellar Clouds ◽

Dark Clouds ◽

Cloud Cores ◽

Many Sources ◽

Cold Dust ◽

Infrared Dark Clouds

AbstractThe project Galactic Cold Cores is studying the early stages of Galactic star formation using far-infrared and sub-millimetre observations of dust emission. The Planck satellite has located many sources of cold dust emission that are likely to be pre-stellar clumps in interstellar clouds. We have mapped a sample of Planck-detected clumps with the Herschel satellite at wavelengths 100-500 μm. Herschel has confirmed the Planck detections of cold dust and have revealed a significant amount of sub-structure in the clumps. The cloud cores have colour temperatures in the range of 10–15 K. However, star formation is often already in progress with cold clumps coinciding with mid-infrared point sources. In less than half of the cases, the cloud morphology is clearly dominated by filamentary structures. The sources include both nearby isolated globules and more distant, massive clouds that may be off-the-plane counterparts of infrared dark clouds.The Herschel observations have been completed and the processed maps will be released to the community in 2013.

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The Cold Dust Content of the Nearby Galaxies IC 5325, NGC 7496, NGC 7590, and NGC 7599

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab1048 ◽

2021 ◽

Author(s):

Swapnil Singh ◽

M L N Ashby ◽

Sarita Vig ◽

S K Ghosh ◽

T Jarrett ◽

...

Keyword(s):

Thermal Emission ◽

Dust Emission ◽

Low Frequency ◽

Dust Content ◽

Spectral Energy ◽

Star Forming ◽

Dust Component ◽

Nearby Galaxies ◽

The Masses ◽

Cold Dust

Abstract Star-forming galaxies are rich reservoirs of dust, both warm and cold. But the cold dust emission is faint alongside the relatively bright and ubiquitous warm dust emission. Recently, evidence for a very cold dust component has also been revealed via millimeter/submillimeter photometry of some galaxies. This component, despite being the most massive of the three dust components in star-forming galaxies, is by virtue of its very low temperature, faint and hard to detect together with the relatively bright emission from warmer dust. Here we analyze the dust content of a carefully selected sample of four galaxies detected by IRAS, WISE, and SPT, whose spectral energy distributions (SEDs) were modeled to constrain their potential cold dust content. Low-frequency radio observations using the GMRT were carried out to segregate cold dust emission from non-thermal emission in millimeter/submillimeter wavebands. We also carried out AstroSat/UVIT observations for some galaxies to constrain their SED at shorter wavelengths so as to enforce energy balance for the SED modeling. We constructed their SEDs across a vast wavelength range (extending from ultraviolet to radio frequencies) by assembling global photometry from GALEX FUV+NUV, UVIT, Johnson BRI, 2MASS, WISE, IRAC, IRAS, AKARI, ISOPHOT, Planck HFI, SPT, and GMRT. The SEDs were modeled with CIGALE to estimate their basic properties, in particular to constrain the masses of their total and very cold dust components. Although the galaxies’ dust masses are dominated by warmer dust, there are hints of very cold dust in two of the targets, NGC 7496 and NGC 7590.

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