Davide Quintino Elia - Academia.edu (original) (raw)

Papers by Davide Quintino Elia

Molecular line transitions at mm-wavelengths are widely used to study spatial distribution and ki... more Molecular line transitions at mm-wavelengths are widely used to study spatial distribution and kinematics of the molecular gas. We present the first results of CO(1-0) line-and 1.2-mm continuum-emission mapping of a molecular cloud in the Vela Molecular Ridge that show the importance of this kind of observations in unveiling the processes underlying diffuse and clustered star formation. These programs require both high resolution and high sensitivity to diffuse gas (hence, a single-dish telescope is needed). Thus, we also discuss the potentialities offered by the SRT to map relatively large regions of molecular gas, in terms of both available molecular transitions and efficiency.

MACHO-96-BLG-5 was a microlensing event observed toward the bulge of the Galaxy with an exception... more MACHO-96-BLG-5 was a microlensing event observed toward the bulge of the Galaxy with an exceptionally long duration of $970 days. The microlensing parallax fit parameters were used to estimate a lens mass M = 6 þ10 À3 M , corresponding to a distance d in the range 0.5Y2 kpc. The upper limit on the absolute brightness for main-sequence stars of the same mass is less than 1 L , so the lens is a good black hole candidate. Such a black hole would accrete from the interstellar medium, thereby emitting in the X-ray band. Here we report the analysis of a deep XMM-Newton observation toward the MACHO-96-BLG-5 lens position. Only an upper limit (99.8% confidence level) to the X-ray flux from the lens position, 9.10 ; 10 À15 to 1.45 ; 10 À14 ergs cm À2 s À1 in the 0.2Y10 keVenergy band, is obtained, allowing us to constrain the putative black hole's accretion parameters.

The VIALACTEA project aims at building a predictive model of star formation in our galaxy. We pre... more The VIALACTEA project aims at building a predictive model of star formation in our galaxy. We present the innovative integrated framework and the main technologies and methodologies to reach this ambitious goal.

Astronomy & Astrophysics, 2021

Context. New-generation spectroscopic surveys of the Milky Way plane have been revealing the stru... more Context. New-generation spectroscopic surveys of the Milky Way plane have been revealing the structure of the interstellar medium, allowing the simultaneous study of dense structures from single star-forming objects or systems to entire spiral arms. Aims. The good sensitivity of the new surveys and the development of dedicated algorithms now enable building extensive catalogues of molecular clouds and deriving good estimates of their physical properties. This allows studying the behaviour of these properties across the Galaxy. Methods. We present the catalogue of molecular clouds extracted from the 13CO (1–0) data cubes of the Forgotten Quadrant Survey, which mapped the Galactic plane in the range 220° < l < 240° and −2.​​° 5 < b < 0° in 12CO (1–0) and 13CO (1–0). We compared the properties of the clouds of our catalogue with those of other catalogues. Results. The catalogue contains 87 molecular clouds for which the main physical parameters such as area, mass, distance,...

This paper presents the latest developments on the VIALACTEA Science Gateway in the context of th... more This paper presents the latest developments on the VIALACTEA Science Gateway in the context of the FP7 VIALACTEA project. This Science Gateway operates as a central workbench for the VIALACTEA community in order to allow astronomers to process the new-generation (from Infrared to Radio) surveys of the Galactic Plane to build and deliver a quantitative 3D model of our Milky Way Galaxy. The final model will be used as a template for external galaxies to study star formation across the cosmic time. The adopted AGILE software development process allowed to fulfill the community needs in terms of required workflows and underlying resources monitoring. The scientific requirements arose during the process highlighted the needs for easy parameter setting, fully embarrassingly parallel computations and large-scale input dataset processing. Therefore the Science Gateway based on the WS-PGRADE/gUSE framework has been able to fulfill the requirements mainly exploiting the parameter sweep paradi...

Monthly Notices of the Royal Astronomical Society, 2016

The degradation of spatial resolution in star-forming regions, observed at large distances (d 1 k... more The degradation of spatial resolution in star-forming regions, observed at large distances (d 1 kpc) with Herschel, can lead to estimates of the physical parameters of the detected compact sources (clumps), which do not necessarily mirror the properties of the original population of cores. This paper aims at quantifying the bias introduced in the estimation of these parameters by the distance effect. To do so, we consider Herschel maps of nearby star-forming regions taken from the Herschel Gould Belt survey, and simulate the effect of increased distance to understand what amount of information is lost when a distant star-forming region is observed with Herschel resolution. In the maps displaced to different distances we extract compact sources, and we derive their physical parameters as if they were original Herschel infrared Galactic Plane Survey maps of the extracted source samples. In this way, we are able to discuss how the main physical properties change with distance. In particular, we discuss the ability of clumps to form massive stars: we estimate the fraction of distant sources that are classified as high-mass stars-forming objects due to their position in the mass versus radius diagram, that are only 'false positives'. We also give a threshold for high-mass star formation M > 1282 r [pc] 1.42 M. In conclusion, this paper provides the astronomer dealing with Herschel maps of distant star-forming regions with a set of prescriptions to partially recover the character of the core population in unresolved clumps.

Future Generation Computer Systems, 2017

This paper presents the latest developments on the VIALACTEA Science Gateway in the context of th... more This paper presents the latest developments on the VIALACTEA Science Gateway in the context of the FP7 VIALACTEA project. The science gateway operates as a central workbench for the VIALACTEA community in order to allow astronomers to process the new-generation surveys (from Infrared to Radio) of the Galactic Plane to build and deliver a quantitative 3D model of our Milky Way Galaxy. The final model will be used as a template for external galaxies to study star formation across the cosmic time. The adopted agile software development process allowed to fulfill the community needs in terms of required workflows and underlying resource monitoring. Scientific requirements arose during the process highlighted the needs for easy parameter setting, fully embarrassingly parallel computations and large-scale input dataset processing. Therefore the science gateway based on the WS-PGRADE/gUSE framework has been able to fulfill the requirements mainly exploiting the parameter sweep paradigm and parallel job execution of the workflow management system.

Monthly Notices of the Royal Astronomical Society, 2015

We positionally match a sample of infrared-selected young stellar objects, identified by combinin... more We positionally match a sample of infrared-selected young stellar objects, identified by combining the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire, Wide-field Infrared Survey Explorer and Herschel Space Observatory Herschel infrared Galactic Plane Survey, to the dense clumps identified in the millimetre continuum by the Bolocam Galactic Plane Survey in two Galactic lines of sight centred towards l = 30 • and 40 •. We calculate the ratio of infrared luminosity, L IR , to the mass of the clump, M clump , in a variety of Galactic environments and find it to be somewhat enhanced in spiral arms compared to the interarm regions when averaged over kiloparsec scales. We find no compelling evidence that these changes are due to the mechanical influence of the spiral arm on the star formation efficiency rather than, e.g. different gradients in the star formation rate due to patchy or intermittent star formation, or local variations that are not averaged out due to small source samples. The largest variation in L IR /M clump is found in individual clump values, which follow a lognormal distribution and have a range of over three orders of magnitude. This spread is intrinsic as no dependence of L IR /M clump with M clump was found. No difference was found in the luminosity distribution of sources in the arm and interarm samples and a strong linear correlation was found between L IR and M clump .

Smart Innovation, Systems and Technologies, 2016

We present an innovative method called FilExSeC (Filaments Extraction, Selection and Classificati... more We present an innovative method called FilExSeC (Filaments Extraction, Selection and Classification), a data mining tool developed to investigate the possibility to refine and optimize the shape reconstruction of filamentary structures detected with a consolidated method based on the flux derivative analysis, through the column-density maps computed from Herschel infrared Galactic Plane Survey (Hi-GAL) observations of the Galactic plane. The present methodology is based on a feature extraction module followed by a machine learning model (Random Forest) dedicated to select features and to classify the pixels of the input images. From tests on both simulations and real observations the method appears reliable and robust with respect to the variability of shape and distribution of filaments. In the cases of highly defined filament structures, the presented method is able to bridge the gaps among the detected fragments, thus improving their shape reconstruction. From a preliminary a posteriori analysis of derived filament physical parameters, the method appears potentially able to add a sufficient contribution to complete and refine the filament reconstruction.

Monthly Notices of the Royal Astronomical Society, 2015

We report high-resolution observations of the 12 CO(1-0) and 13 CO(1-0) molecular lines in the Ca... more We report high-resolution observations of the 12 CO(1-0) and 13 CO(1-0) molecular lines in the Carina Nebula and the Gum 31 region obtained with the 22-m Mopra telescope as part of The Mopra Southern Galactic Plane CO Survey. We cover 8 deg 2 from l = 285 • to 290 • , and from b = −1. • 5 to +0. • 5. The molecular gas column density distributions from both tracers have a similar range of values. By fitting a grey-body function to the observed infrared spectral energy distribution from Herschel maps, we derive gas column densities and dust temperatures. The gas column density has values in the range from 6.3 × 10 20 to 1.4 × 10 23 cm −2 , while the dust temperature has values in the range from 17 to 43 K. The gas column density derived from the dust emission is approximately described by a lognormal function for a limited range of column densities. A high-column-density tail is clearly evident for the gas column density distribution, which appears to be a common feature in regions with active star formation. There are regional variations in the fraction of the mass recovered by the CO emission lines with respect to the total mass traced by the dust emission. These variations may be related to changes in the radiation field strength, variation of the atomic to molecular gas fraction across the observed region, differences in the CO molecule abundance with respect to H 2 , and evolutionary stage differences of the molecular clouds that compose the Carina Nebula-Gum 31 complex.

Monthly Notices of the Royal Astronomical Society, 2015

We report the discovery of a new young stellar cluster in the outer Galaxy located at the positio... more We report the discovery of a new young stellar cluster in the outer Galaxy located at the position of an IRAS PSC source that has been previously mis-identified as an external galaxy. The cluster is seen in our near-infrared imaging towards IRAS 04186+5143 and in archive Spitzer images confirming the young stellar nature of the sources detected. There is also evidence of sub-clustering seen in the spatial distributions of young stars and of gas and dust. Near-and mid-infrared photometry indicates that the stars exhibit colours compatible with reddening by interstellar and circumstellar dust and are likely to be lowand intermediate-mass YSOs with a large proportion of Class I YSOs. Ammonia and CO lines were detected, with the CO emission well centred near the position of the richest part of the cluster. The velocity of the CO and NH 3 lines indicates that the gas is Galactic and located at a distance of about 5.5 kpc, in the outer Galaxy. Herschel data of this region characterise the dust environment of this molecular cloud core where the young cluster is embedded. We derive masses, luminosities and temperatures of the molecular clumps where the young stars reside and discuss their evolutionary stages.

The files are the Mopra telescope data cubes used to produce the maps in Fig.A1. Units are Ta*[K]... more The files are the Mopra telescope data cubes used to produce the maps in Fig.A1. Units are Ta*[K]. Data cubes are not reduced. Noise in the maps is not uniform. Frequency resolution is 33.7kHz. (2 data files).

File yso.dat contains the photometry and distances of the identified Young Stellar Objects (YSO) ... more File yso.dat contains the photometry and distances of the identified Young Stellar Objects (YSO) in two 2x2 tiles of the Herschel-Hi-GAL survey. The fields are centered in (l,b)=(30,0) and (l,b)=(59,0). The detection and photometry from 24 micron to 500 micron have been extracted with the CuTEX algorithm (Molinari et al., 2011A&A...530A.133M) while the kinematic distances have been estimated by Russeil et al. (2011, Cat. J/A+A/526/A151). (1 data file).

G29.96-0.02 is a high-mass star-forming cloud observed at 70, 160, 250, 350, and 500μm as part of... more G29.96-0.02 is a high-mass star-forming cloud observed at 70, 160, 250, 350, and 500μm as part of the Herschel survey of the Galactic plane (Hi-GAL) during the science demonstration phase. We wish to conduct a far-infrared study of the sources associated with this star-forming region by estimating their physical properties and evolutionary stage, and investigating the clump mass function, the star formation efficiency and rate in the cloud. We have identified the Hi-GAL sources associated with the cloud, searched for possible counterparts at centimeter and infrared wavelengths, fitted their spectral energy distribution and estimated their physical parameters. (3 data files).

We present the first results of a large-scale map of the galactic Giant Molecular Cloud Vela C, i... more We present the first results of a large-scale map of the galactic Giant Molecular Cloud Vela C, in the 345-GHz continuum. The observations were carried out with the LABOCA bolometer array at APEX. We discuss the spatial distribution of dust cores in the region, their physical properties and the derived Core Mass Function.

Interactions between the interstellar medium (ISM) and young stellar objects (YSO) need to be inv... more Interactions between the interstellar medium (ISM) and young stellar objects (YSO) need to be investigated to better understand star formation. We used the Minimum Spanning Tree (MST) method to identify protostellar clusters in the inner part of galactic plane. Using heliocentric distance estimates, we obtained about 230 clusters over a 140 × 2 square degree region. Most of these clusters are correlated with Infrared Dark Cloud (IRDC) or H II regions. We conclude that clustering is more important for protostars than for prestellar clumps and that a strong correlation can be established between the distribution of H II regions, known star formation complexes and the YSOs identified in the Hi-GAL data.

Astrophysics and Space Science, 2014

Flux variability is a common feature of Young Stellar Objects (YSOs), which is often related to i... more Flux variability is a common feature of Young Stellar Objects (YSOs), which is often related to intermittent events of disk accretion (EXors events in case of 3-4 magnitudes variations). Recently, thanks to the surveys carried out by the space missions Spitzer and WISE, it has become possible to perform statistical studies on the mid-IR variability on large samples of YSOs. As a follow-up of our recent statistical study on five star forming regions (Antoniucci et al., Astrophys. J. 782:51, 2014), we present the 3-5 µm variability study of the YSOs population of the Vela-D star forming region. We have compared the 3.6 µm and 4.5 µm Spitzer-IRAC fluxes of 181 YSOs in Vela-D with their WISE fluxes at 3.4 µm and 4.6 µm and selected those objects simultaneously varying in both bands. We have identified a robust sample of 34 variables. On the base of the infrared excess of the Spectral Energy Distribution (SED) and the magnitude vs. color variations, we select 5 EXors candidates, which will be systematically monitored to firmly ascertain their nature. The selected 34 variables represent ∼18 % of the YSOs detected with Spitzer and WISE, a percentage higher than that of other young star forming regions. Conversely, the percentage of candidate EXors (2.7 %) is quite similar to that measured in Perseus, Ophiuchus and

Molecular line transitions at mm-wavelengths are widely used to study spatial distribution and ki... more Molecular line transitions at mm-wavelengths are widely used to study spatial distribution and kinematics of the molecular gas. We present the first results of CO(1-0) line-and 1.2-mm continuum-emission mapping of a molecular cloud in the Vela Molecular Ridge that show the importance of this kind of observations in unveiling the processes underlying diffuse and clustered star formation. These programs require both high resolution and high sensitivity to diffuse gas (hence, a single-dish telescope is needed). Thus, we also discuss the potentialities offered by the SRT to map relatively large regions of molecular gas, in terms of both available molecular transitions and efficiency.

MACHO-96-BLG-5 was a microlensing event observed toward the bulge of the Galaxy with an exception... more MACHO-96-BLG-5 was a microlensing event observed toward the bulge of the Galaxy with an exceptionally long duration of $970 days. The microlensing parallax fit parameters were used to estimate a lens mass M = 6 þ10 À3 M , corresponding to a distance d in the range 0.5Y2 kpc. The upper limit on the absolute brightness for main-sequence stars of the same mass is less than 1 L , so the lens is a good black hole candidate. Such a black hole would accrete from the interstellar medium, thereby emitting in the X-ray band. Here we report the analysis of a deep XMM-Newton observation toward the MACHO-96-BLG-5 lens position. Only an upper limit (99.8% confidence level) to the X-ray flux from the lens position, 9.10 ; 10 À15 to 1.45 ; 10 À14 ergs cm À2 s À1 in the 0.2Y10 keVenergy band, is obtained, allowing us to constrain the putative black hole's accretion parameters.

The VIALACTEA project aims at building a predictive model of star formation in our galaxy. We pre... more The VIALACTEA project aims at building a predictive model of star formation in our galaxy. We present the innovative integrated framework and the main technologies and methodologies to reach this ambitious goal.

Astronomy & Astrophysics, 2021

Context. New-generation spectroscopic surveys of the Milky Way plane have been revealing the stru... more Context. New-generation spectroscopic surveys of the Milky Way plane have been revealing the structure of the interstellar medium, allowing the simultaneous study of dense structures from single star-forming objects or systems to entire spiral arms. Aims. The good sensitivity of the new surveys and the development of dedicated algorithms now enable building extensive catalogues of molecular clouds and deriving good estimates of their physical properties. This allows studying the behaviour of these properties across the Galaxy. Methods. We present the catalogue of molecular clouds extracted from the 13CO (1–0) data cubes of the Forgotten Quadrant Survey, which mapped the Galactic plane in the range 220° < l < 240° and −2.​​° 5 < b < 0° in 12CO (1–0) and 13CO (1–0). We compared the properties of the clouds of our catalogue with those of other catalogues. Results. The catalogue contains 87 molecular clouds for which the main physical parameters such as area, mass, distance,...

This paper presents the latest developments on the VIALACTEA Science Gateway in the context of th... more This paper presents the latest developments on the VIALACTEA Science Gateway in the context of the FP7 VIALACTEA project. This Science Gateway operates as a central workbench for the VIALACTEA community in order to allow astronomers to process the new-generation (from Infrared to Radio) surveys of the Galactic Plane to build and deliver a quantitative 3D model of our Milky Way Galaxy. The final model will be used as a template for external galaxies to study star formation across the cosmic time. The adopted AGILE software development process allowed to fulfill the community needs in terms of required workflows and underlying resources monitoring. The scientific requirements arose during the process highlighted the needs for easy parameter setting, fully embarrassingly parallel computations and large-scale input dataset processing. Therefore the Science Gateway based on the WS-PGRADE/gUSE framework has been able to fulfill the requirements mainly exploiting the parameter sweep paradi...

Monthly Notices of the Royal Astronomical Society, 2016

The degradation of spatial resolution in star-forming regions, observed at large distances (d 1 k... more The degradation of spatial resolution in star-forming regions, observed at large distances (d 1 kpc) with Herschel, can lead to estimates of the physical parameters of the detected compact sources (clumps), which do not necessarily mirror the properties of the original population of cores. This paper aims at quantifying the bias introduced in the estimation of these parameters by the distance effect. To do so, we consider Herschel maps of nearby star-forming regions taken from the Herschel Gould Belt survey, and simulate the effect of increased distance to understand what amount of information is lost when a distant star-forming region is observed with Herschel resolution. In the maps displaced to different distances we extract compact sources, and we derive their physical parameters as if they were original Herschel infrared Galactic Plane Survey maps of the extracted source samples. In this way, we are able to discuss how the main physical properties change with distance. In particular, we discuss the ability of clumps to form massive stars: we estimate the fraction of distant sources that are classified as high-mass stars-forming objects due to their position in the mass versus radius diagram, that are only 'false positives'. We also give a threshold for high-mass star formation M > 1282 r [pc] 1.42 M. In conclusion, this paper provides the astronomer dealing with Herschel maps of distant star-forming regions with a set of prescriptions to partially recover the character of the core population in unresolved clumps.

Future Generation Computer Systems, 2017

This paper presents the latest developments on the VIALACTEA Science Gateway in the context of th... more This paper presents the latest developments on the VIALACTEA Science Gateway in the context of the FP7 VIALACTEA project. The science gateway operates as a central workbench for the VIALACTEA community in order to allow astronomers to process the new-generation surveys (from Infrared to Radio) of the Galactic Plane to build and deliver a quantitative 3D model of our Milky Way Galaxy. The final model will be used as a template for external galaxies to study star formation across the cosmic time. The adopted agile software development process allowed to fulfill the community needs in terms of required workflows and underlying resource monitoring. Scientific requirements arose during the process highlighted the needs for easy parameter setting, fully embarrassingly parallel computations and large-scale input dataset processing. Therefore the science gateway based on the WS-PGRADE/gUSE framework has been able to fulfill the requirements mainly exploiting the parameter sweep paradigm and parallel job execution of the workflow management system.

Monthly Notices of the Royal Astronomical Society, 2015

We positionally match a sample of infrared-selected young stellar objects, identified by combinin... more We positionally match a sample of infrared-selected young stellar objects, identified by combining the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire, Wide-field Infrared Survey Explorer and Herschel Space Observatory Herschel infrared Galactic Plane Survey, to the dense clumps identified in the millimetre continuum by the Bolocam Galactic Plane Survey in two Galactic lines of sight centred towards l = 30 • and 40 •. We calculate the ratio of infrared luminosity, L IR , to the mass of the clump, M clump , in a variety of Galactic environments and find it to be somewhat enhanced in spiral arms compared to the interarm regions when averaged over kiloparsec scales. We find no compelling evidence that these changes are due to the mechanical influence of the spiral arm on the star formation efficiency rather than, e.g. different gradients in the star formation rate due to patchy or intermittent star formation, or local variations that are not averaged out due to small source samples. The largest variation in L IR /M clump is found in individual clump values, which follow a lognormal distribution and have a range of over three orders of magnitude. This spread is intrinsic as no dependence of L IR /M clump with M clump was found. No difference was found in the luminosity distribution of sources in the arm and interarm samples and a strong linear correlation was found between L IR and M clump .

Smart Innovation, Systems and Technologies, 2016

We present an innovative method called FilExSeC (Filaments Extraction, Selection and Classificati... more We present an innovative method called FilExSeC (Filaments Extraction, Selection and Classification), a data mining tool developed to investigate the possibility to refine and optimize the shape reconstruction of filamentary structures detected with a consolidated method based on the flux derivative analysis, through the column-density maps computed from Herschel infrared Galactic Plane Survey (Hi-GAL) observations of the Galactic plane. The present methodology is based on a feature extraction module followed by a machine learning model (Random Forest) dedicated to select features and to classify the pixels of the input images. From tests on both simulations and real observations the method appears reliable and robust with respect to the variability of shape and distribution of filaments. In the cases of highly defined filament structures, the presented method is able to bridge the gaps among the detected fragments, thus improving their shape reconstruction. From a preliminary a posteriori analysis of derived filament physical parameters, the method appears potentially able to add a sufficient contribution to complete and refine the filament reconstruction.

Monthly Notices of the Royal Astronomical Society, 2015

We report high-resolution observations of the 12 CO(1-0) and 13 CO(1-0) molecular lines in the Ca... more We report high-resolution observations of the 12 CO(1-0) and 13 CO(1-0) molecular lines in the Carina Nebula and the Gum 31 region obtained with the 22-m Mopra telescope as part of The Mopra Southern Galactic Plane CO Survey. We cover 8 deg 2 from l = 285 • to 290 • , and from b = −1. • 5 to +0. • 5. The molecular gas column density distributions from both tracers have a similar range of values. By fitting a grey-body function to the observed infrared spectral energy distribution from Herschel maps, we derive gas column densities and dust temperatures. The gas column density has values in the range from 6.3 × 10 20 to 1.4 × 10 23 cm −2 , while the dust temperature has values in the range from 17 to 43 K. The gas column density derived from the dust emission is approximately described by a lognormal function for a limited range of column densities. A high-column-density tail is clearly evident for the gas column density distribution, which appears to be a common feature in regions with active star formation. There are regional variations in the fraction of the mass recovered by the CO emission lines with respect to the total mass traced by the dust emission. These variations may be related to changes in the radiation field strength, variation of the atomic to molecular gas fraction across the observed region, differences in the CO molecule abundance with respect to H 2 , and evolutionary stage differences of the molecular clouds that compose the Carina Nebula-Gum 31 complex.

Monthly Notices of the Royal Astronomical Society, 2015

We report the discovery of a new young stellar cluster in the outer Galaxy located at the positio... more We report the discovery of a new young stellar cluster in the outer Galaxy located at the position of an IRAS PSC source that has been previously mis-identified as an external galaxy. The cluster is seen in our near-infrared imaging towards IRAS 04186+5143 and in archive Spitzer images confirming the young stellar nature of the sources detected. There is also evidence of sub-clustering seen in the spatial distributions of young stars and of gas and dust. Near-and mid-infrared photometry indicates that the stars exhibit colours compatible with reddening by interstellar and circumstellar dust and are likely to be lowand intermediate-mass YSOs with a large proportion of Class I YSOs. Ammonia and CO lines were detected, with the CO emission well centred near the position of the richest part of the cluster. The velocity of the CO and NH 3 lines indicates that the gas is Galactic and located at a distance of about 5.5 kpc, in the outer Galaxy. Herschel data of this region characterise the dust environment of this molecular cloud core where the young cluster is embedded. We derive masses, luminosities and temperatures of the molecular clumps where the young stars reside and discuss their evolutionary stages.

The files are the Mopra telescope data cubes used to produce the maps in Fig.A1. Units are Ta*[K]... more The files are the Mopra telescope data cubes used to produce the maps in Fig.A1. Units are Ta*[K]. Data cubes are not reduced. Noise in the maps is not uniform. Frequency resolution is 33.7kHz. (2 data files).

File yso.dat contains the photometry and distances of the identified Young Stellar Objects (YSO) ... more File yso.dat contains the photometry and distances of the identified Young Stellar Objects (YSO) in two 2x2 tiles of the Herschel-Hi-GAL survey. The fields are centered in (l,b)=(30,0) and (l,b)=(59,0). The detection and photometry from 24 micron to 500 micron have been extracted with the CuTEX algorithm (Molinari et al., 2011A&A...530A.133M) while the kinematic distances have been estimated by Russeil et al. (2011, Cat. J/A+A/526/A151). (1 data file).

G29.96-0.02 is a high-mass star-forming cloud observed at 70, 160, 250, 350, and 500μm as part of... more G29.96-0.02 is a high-mass star-forming cloud observed at 70, 160, 250, 350, and 500μm as part of the Herschel survey of the Galactic plane (Hi-GAL) during the science demonstration phase. We wish to conduct a far-infrared study of the sources associated with this star-forming region by estimating their physical properties and evolutionary stage, and investigating the clump mass function, the star formation efficiency and rate in the cloud. We have identified the Hi-GAL sources associated with the cloud, searched for possible counterparts at centimeter and infrared wavelengths, fitted their spectral energy distribution and estimated their physical parameters. (3 data files).

We present the first results of a large-scale map of the galactic Giant Molecular Cloud Vela C, i... more We present the first results of a large-scale map of the galactic Giant Molecular Cloud Vela C, in the 345-GHz continuum. The observations were carried out with the LABOCA bolometer array at APEX. We discuss the spatial distribution of dust cores in the region, their physical properties and the derived Core Mass Function.

Interactions between the interstellar medium (ISM) and young stellar objects (YSO) need to be inv... more Interactions between the interstellar medium (ISM) and young stellar objects (YSO) need to be investigated to better understand star formation. We used the Minimum Spanning Tree (MST) method to identify protostellar clusters in the inner part of galactic plane. Using heliocentric distance estimates, we obtained about 230 clusters over a 140 × 2 square degree region. Most of these clusters are correlated with Infrared Dark Cloud (IRDC) or H II regions. We conclude that clustering is more important for protostars than for prestellar clumps and that a strong correlation can be established between the distribution of H II regions, known star formation complexes and the YSOs identified in the Hi-GAL data.

Astrophysics and Space Science, 2014

Flux variability is a common feature of Young Stellar Objects (YSOs), which is often related to i... more Flux variability is a common feature of Young Stellar Objects (YSOs), which is often related to intermittent events of disk accretion (EXors events in case of 3-4 magnitudes variations). Recently, thanks to the surveys carried out by the space missions Spitzer and WISE, it has become possible to perform statistical studies on the mid-IR variability on large samples of YSOs. As a follow-up of our recent statistical study on five star forming regions (Antoniucci et al., Astrophys. J. 782:51, 2014), we present the 3-5 µm variability study of the YSOs population of the Vela-D star forming region. We have compared the 3.6 µm and 4.5 µm Spitzer-IRAC fluxes of 181 YSOs in Vela-D with their WISE fluxes at 3.4 µm and 4.6 µm and selected those objects simultaneously varying in both bands. We have identified a robust sample of 34 variables. On the base of the infrared excess of the Spectral Energy Distribution (SED) and the magnitude vs. color variations, we select 5 EXors candidates, which will be systematically monitored to firmly ascertain their nature. The selected 34 variables represent ∼18 % of the YSOs detected with Spitzer and WISE, a percentage higher than that of other young star forming regions. Conversely, the percentage of candidate EXors (2.7 %) is quite similar to that measured in Perseus, Ophiuchus and