39 research outputs found
NIKA2 observations of dust grain evolution from star-forming filament to T-Tauri disk: Preliminary results from NIKA2 observations of the Taurus B211/B213 filament
To understand the evolution of dust properties in molecular clouds in the
course of the star formation process, we constrain the changes in the dust
emissivity index from star-forming filaments to prestellar and protostellar
cores to T Tauri stars. Using the NIKA2 continuum camera on the IRAM 30~m
telescope, we observed the Taurus B211/B213 filament at 1.2\,mm and 2\,mm with
unprecedented sensitivity and used the resulting maps to derive the dust
emissivity index . Our sample of 105 objects detected in the map
of the B211/B213 filament indicates that, overall, decreases from
filament and prestellar cores () to protostellar cores
() to T-Tauri protoplanetary disk (). The
averaged dust emissivity index across the B211/B213 filament exhibits a
flat () profile. This may imply that dust grain sizes are
rather homogeneous in the filament, start to grow significantly in size only
after the onset of the gravitational contraction/collapse of prestellar cores
to protostars, reaching big sizes in T Tauri protoplanetary disks. This
evolution from the parent filament to T-Tauri disks happens on a timescale of
about 1-2~Myr.Comment: to appear in Proc. of the mm Universe 2023 conference, Grenoble
(France), June 2023, published by F. Mayet et al. (Eds), EPJ Web of
conferences, EDP Science
IAS/CEA Evolution of Dust in Nearby Galaxies (ICED): the spatially-resolved dust properties of NGC4254
We present the first preliminary results of the project \textit{ICED},
focusing on the face-on galaxy NGC4254. We use the millimetre maps observed
with NIKA2 at IRAM-30m, as part of the IMEGIN Guaranteed Time Large Program,
and of a wide collection of ancillary data (multi-wavelength photometry and gas
phase spectral lines) that are publicly available. We derive the global and
local properties of interstellar dust grains through infrared-to-radio spectral
energy distribution fitting, using the hierarchical Bayesian code HerBIE, which
includes the grain properties of the state-of-the-art dust model, THEMIS. Our
method allows us to get the following dust parameters: dust mass, average
interstellar radiation field, and fraction of small grains. Also, it is
effective in retrieving the intrinsic correlations between dust parameters and
interstellar medium properties. We find an evident anti-correlation between the
interstellar radiation field and the fraction of small grains in the centre of
NGC4254, meaning that, at strong radiation field intensities, very small
amorphous carbon grains are efficiently destroyed by the ultra-violet photons
coming from newly formed stars, through photo-desorption and sublimation. We
observe a flattening of the anti-correlation at larger radial distances, which
may be driven by the steep metallicity gradient measured in NGC4254.Comment: to appear in Proc. of the mm Universe 2023 conference, Grenoble
(France), June 2023, published by F. Mayet et al. (Eds), EPJ Web of
conferences, EDP Science
Exploring the interstellar medium of NGC 891 at millimeter wavelengths using the NIKA2 camera
In the framework of the IMEGIN Large Program, we used the NIKA2 camera on the
IRAM 30-m telescope to observe the edge-on galaxy NGC 891 at 1.15 mm and 2 mm
and at a FWHM of 11.1" and 17.6", respectively. Multiwavelength data enriched
with the new NIKA2 observations fitted by the HerBIE SED code (coupled with the
THEMIS dust model) were used to constrain the physical properties of the ISM.
Emission originating from the diffuse dust disk is detected at all wavelengths
from mid-IR to mm, while mid-IR observations reveal warm dust emission from
compact HII regions. Indications of mm excess emission have also been found in
the outer parts of the galactic disk. Furthermore, our SED fitting analysis
constrained the mass fraction of the small (< 15 Angstrom) dust grains. We
found that small grains constitute 9.5% of the total dust mass in the galactic
plane, but this fraction increases up to ~ 20% at large distances (|z| > 3 kpc)
from the galactic plane.Comment: To appear in Proc. of the mm Universe 2023 conference, Grenoble
(France), June 2023, published by F. Mayet et al. (Eds), EPJ Web of
conferences, EDP Science
The physical properties of local (U)LIRGs: A comparison with nearby early- And late-type galaxies
Aims. In order to pinpoint the place of the (ultra-) luminous infrared galaxies ((U)LIRGs) in the local Universe, we examine the properties of a sample of 67 such nearby systems and compare them with those of 268 early- and 542 late-type, well studied, galaxies from the DustPedia database. Methods. We made use of multi-wavelength photometric data (from the ultra-violet to the sub-millimetre), culled from the literature, and the CIGALE spectral energy distribution fitting code to extract the physical parameters of each system. The median spectral energy distributions as well as the values of the derived parameters were compared to those of the local early- and late-type galaxies. In addition to that, (U)LIRGs were divided into seven classes, according to the merging stage of each system, and variations in the derived parameters were investigated. Results. (U)LIRGs occupy the 'high-end' on the dust mass, stellar mass, and star-formation rate (SFR) plane in the local Universe with median values of 5.2 à 107 Mpdbl, 6.3 à 1010 Mpdbl, and 52 Mpdblyr-1, respectively. The median value of the dust temperature in (U)LIRGs is 32 K, which is higher compared to both the early-type (28 K) and the late-type (22 K) galaxies. The dust emission in PDR regions in (U)LIRGs is 11.7% of the total dust luminosity, which is significantly higher than early-type (1.6%) and late-type (5.2%) galaxies. Small differences in the derived parameters are seen for the seven merging classes of our sample of (U)LIRGs with the most evident one being on the SFR, where in systems in late merging stages ('M3' and 'M4') the median SFR reaches up to 99 Mpdblyr-1compared to 26 Mpdblyr-1for the isolated ones. In contrast to the local early-and late-type galaxies where the old stars are the dominant source of the stellar emission, the young stars in (U)LIRGs contribute with 64% of their luminosity to the total stellar luminosity. The fraction of the stellar luminosity absorbed by the dust is extremely high in (U)LIRGs (78%) compared to 7% and 25% in early- and late-type galaxies, respectively. The fraction of the stellar luminosity used to heat up the dust grains is very high in (U)LIRGs, for both stellar components (92% and 56% for the young and the old stellar populations, respectively) while 74% of the dust emission comes from the young stars. © ESO 2021
The physical properties of local (U)LIRGs: A comparison with nearby early- and late-type galaxies
Aims. In order to pinpoint the place of the (ultra-) luminous infrared galaxies ((U)LIRGs) in the local Universe, we examine the properties of a sample of 67 such nearby systems and compare them with those of 268 early- and 542 late-type, well studied, galaxies from the DustPedia database.
Methods. We made use of multi-wavelength photometric data (from the ultra-violet to the sub-millimetre), culled from the literature, and the CIGAL
Systematic effects on the upcoming NIKA2 LPSZ scaling relation
In cluster cosmology, cluster masses are the main parameter of interest. They are needed to constrain cosmological parameters through the cluster number count. As the mass is not an observable, a scaling relation is needed to link cluster masses to the integrated Compton parameters Y, i.e. the Sunyaev-Zeldovich observable (SZ). Planck cosmological results obtained with cluster number counts are based on a scaling relation measured with clusters at low redshift (z<0.5) observed in SZ and X-ray. In the SZ Large Program (LPSZ) of the NIKA2 collaboration, the scaling relation will be obtained with a sample of 38 clusters at intermediate to high redshift (0.5 < z < 0.9) and observed at high angular resolution in both SZ and X-ray. Thanks to analytical simulation of LPSZ-like samples, we take into account the LPSZ selection function and correct for its effects. Besides, we show that white and correlated noises in the SZ maps do not affect the scaling relation estimation
Systematic effects on the upcoming NIKA2 LPSZ scaling relation
International audienceIn cluster cosmology, cluster masses are the main parameter of interest. They are needed to constrain cosmological parameters through the cluster number count. As the mass is not an observable, a scaling relation is needed to link cluster masses to the integrated Compton parameters Y, i.e. the Sunyaev-Zeldovich observable (SZ). Planck cosmological results obtained with cluster number counts are based on a scaling relation measured with clusters at low redshift (<0.5) observed in SZ and X-ray. In the SZ Large Program (LPSZ) of the NIKA2 collaboration, the scaling relation will be obtained with a sample of 38 clusters at intermediate to high redshift () and observed at high angular resolution in both SZ and X-ray. Thanks to analytical simulation of LPSZ-like samples, we take into account the LPSZ selection function and correct for its effects. Besides, we show that white and correlated noises in the SZ maps do not affect the scaling relation estimation
Systematic effects on the upcoming NIKA2 LPSZ scaling relation
International audienceIn cluster cosmology, cluster masses are the main parameter of interest. They are needed to constrain cosmological parameters through the cluster number count. As the mass is not an observable, a scaling relation is needed to link cluster masses to the integrated Compton parameters Y, i.e. the Sunyaev-Zeldovich observable (SZ). Planck cosmological results obtained with cluster number counts are based on a scaling relation measured with clusters at low redshift (<0.5) observed in SZ and X-ray. In the SZ Large Program (LPSZ) of the NIKA2 collaboration, the scaling relation will be obtained with a sample of 38 clusters at intermediate to high redshift () and observed at high angular resolution in both SZ and X-ray. Thanks to analytical simulation of LPSZ-like samples, we take into account the LPSZ selection function and correct for its effects. Besides, we show that white and correlated noises in the SZ maps do not affect the scaling relation estimation
Systematic effects on the upcoming NIKA2 LPSZ scaling relation
International audienceIn cluster cosmology, cluster masses are the main parameter of interest. They are needed to constrain cosmological parameters through the cluster number count. As the mass is not an observable, a scaling relation is needed to link cluster masses to the integrated Compton parameters Y, i.e. the Sunyaev-Zeldovich observable (SZ). Planck cosmological results obtained with cluster number counts are based on a scaling relation measured with clusters at low redshift (<0.5) observed in SZ and X-ray. In the SZ Large Program (LPSZ) of the NIKA2 collaboration, the scaling relation will be obtained with a sample of 38 clusters at intermediate to high redshift () and observed at high angular resolution in both SZ and X-ray. Thanks to analytical simulation of LPSZ-like samples, we take into account the LPSZ selection function and correct for its effects. Besides, we show that white and correlated noises in the SZ maps do not affect the scaling relation estimation
Towards the first mean pressure profile estimate with the NIKA2 Sunyaev-Zeldovich Large Program
International audienceHigh-resolution mapping of the hot gas in galaxy clusters is a key tool for cluster-based cosmological analyses. Taking advantage of the NIKA2 millimeter camera operated at the IRAM 30-m telescope, the NIKA2 SZ Large Program seeks to get a high-resolution follow-up of 38 galaxy clusters covering a wide mass range at intermediate to high redshift. The measured SZ fluxes will be essential to calibrate the SZ scaling relation and the galaxy clusters mean pressure profile, needed for the cosmological exploitation of SZ surveys. We present in this study a method to infer a mean pressure profile from cluster observations. We have designed a pipeline encompassing the map-making and the thermodynamical properties estimates from maps. We then combine all the individual fits, propagating the uncertainties on integrated quantities, such as or , and the intrinsic scatter coming from the deviation to the standard self-similar model. We validate the proposed method on realistic LPSZ-like cluster simulations