FQS è un programma basato su 700 ore di osservazione di 12CO(1-0) and 13CO(1-0) in 50 gradi quadrati del piano della Via Lattea (220°<l<240°, -2.5°<b<0°) con l'antenna di 12m del Arizona Radio Observatory. Questi dati hanno rivelato la disposizione del gas molecolare in strutture sempre più dense e piccole, partendo dai bracci a spirale, definiti dalle nubi molecolari giganti, con la loro rete di filamenti, fino ai clumps e cores dove si formano le stelle. Il dataset di FQS, con il suo grande valore di legacy, ha notevolmente aumentato la qualità dei dati molecolari disponibili in precedenza. Nei dati si FQS possono identificare strutture molecolari a varie scale spaziali e derivarne la distanza, ottenendo cosi stime corrette di parametri fisici essenziali quali dimensione e massa.
FQS is a large program that used 700 hr of the 12m antenna at the Arizona Radio Observatory to map 50 square degree of the Milky Way plane (220°<l<240°, -2.5°<b<0°) in 12CO(1-0) and 13CO(1-0). These data have shown how the molecular dense gas is organised at different spatial scales: from spiral arms traced by the giant clouds with their denser filamentary networks, down to the clumps and cores that host the new-born stars. FQS produced a dataset of great legacy value, largely improving the quality of both sensitivity and spatial resolution over previous data sets. From these high-quality spectroscopic data we can identify molecular structures at different scales and derive the distance of the emitting gas, obtaining reliable estimates of key physical parameters such as size and mass.
Mezzo interstellare, formazione di stelle e sistemi planetari
Infrastrutture da Terra (utilizzo)
Infrastrutture dallo spazio per l’osservazione dell Universo (utilizzo)
Team Summary
15. Personale INAF coinvolto
Numero di partecipanti INAF al progetto: 14
Struttura
Nfte
N0
TI 2022
TI 2023
TI 2024
TD 2022
TD 2023
TD 2024
Nex
Extra
IAPS ROMA
5
0
0.40
0.60
0.00
0
0
0
1
0.10
O.A. ARCETRI
2
0
0.20
0.20
0.00
0
0
0
0
0.00
IRA BOLOGNA
2
0
0.10
0.20
0.00
0
0
0
0
0.00
Totali
9
0
0.70
1.00
0.00
0.00
0.00
0.00
1
0.10
Fondi a sostegno
21. Totale fondi a disposizione (dato aggregato, k€)
Certi 2022
Certi 2023
Certi 2024
Presunti 2022
Presunti 2023
Presunti 2024
0
0
0
0
0
0
Produzione scientifica e tecnologica
22. Produzione scientifica e tecnologica - Highlights
#
DOI
Descrizione
Azione
1
10.1051/0004-6361/201936096
titolo: The Forgotten Quadrant Survey. 12CO and 13CO (1-0) survey of the Galactic plane in the range 220° <l <240° -2.°5 < b < 0°
autori: Benedettini, M.; Molinari, S.; Baldeschi, A.; Beltrán, M. T.; Brand, J.; Cesaroni, R.; Elia, D.; Fontani, F.; Merello, M.; Olmi, L.; Pezzuto, S.; Rygl, K. L. J.; Schisano, E.; Testi, L.; Traficante, A.
Abstract:
Aims: We present the Forgotten Quadrant Survey (FQS), an ESO large project that used the 12 m antenna of the Arizona Radio Observatory to map the Galactic plane in the range 220° < l < 240° and -2.°5 < b < 0°, both in 12CO (1-0) and 13CO (1-0), at a spectral resolution of 0.65 km s-1 and 0.26 km s-1.
Methods: We used the (1-0) transition of carbon monoxide to trace the molecular component of the interstellar medium. Our data set allows us to easily identify how the molecular dense gas is organised at different spatial scales: from the giant clouds with their denser filamentary networks, down to the clumps and cores that host the new-born stars and to obtain reliable estimates of their key physical parameters such as size and mass.
Results: We present the first release of the data of the FQS survey and discuss their quality. Spectra with 0.65 km s-1 velocity channels have noise ranging from 0.8 K to 1.3 K for 12CO (1-0) and from 0.3 K to 0.6 K for 13CO (1-0). In this first paper, we used the 12CO (1-0) spectral cubes to produce a catalogue of 263 molecular clouds. The clouds are grouped in three main structures corresponding to the Local, Perseus, and Outer arms up to a distance of ˜8.6 kpc from the Sun. This is the first self-consistent statistical catalogue of molecular clouds of the outer Galaxy obtained with a subarcminute spatial resolution and therefore able to detect not only the classical giant molecular clouds, but also the small clouds and to resolve the cloud structure at the sub-parsec scale up to a distance of a few kiloparsec. We found two classes of objects: structures with sizes above a few parsecs that are typical molecular clouds and may be self-gravitating, and subparsec structures that cannot be in gravitational equilibrium and are likely transient or confined by external pressure. We used the ratio between the Herschel H2 column density and the integrated intensity of the CO lines to calculate the CO conversion factor and we found mean values of (3.3 ± 1.4) × 1020 cm-2 (K km s-1)-1 and (1.2 ± 0.4) × 1021 cm-2 (K km s-1)-1, for 12CO (1-0) and 13CO (1-0), respectively.
Conclusions: The FQS contributes to the general effort in producing a new generation of high-quality spectroscopic data for the Galactic plane in the less-studied third Galactic quadrant toward the outer Galaxy. The FQS has produced a data set of great legacy value, largely improving the data quality both in terms of sensitivity and spatial resolution over previous data sets.
2
10.1051/0004-6361/202141433
Molecular cloud catalogue from 13CO (1-0) data of the Forgotten Quadrant Survey
Benedettini, M.; Traficante, A.; Olmi, L.; Pezzuto, S.; Baldeschi, A. ; Molinari, S. ; Elia, D.; Schisano, E.; Merello, M.; Fontani, F; Rygl, K. L. J.; Brand, J.; Beltrán, M. T.; Cesaroni, R.; Liu, S. J. ; Testi, L.
Abstract
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, velocity dispersion, and virial parameter were derived. These structures are overall less extended and less massive than the molecular clouds identified in the 12CO (1-0) data-set because they trace the brightest and densest part of the 12CO (1-0) clouds. Conversely, the distribution of aspect ratio, equivalent spherical radius, velocity dispersion, and virial parameter in the two catalogues are similar. The mean value of the mass surface density of molecular clouds is 87 ± 55 M⊙ pc−2 and is almost constant across the galactocentric radius, indicating that this parameter, which is a proxy of star formation, is mostly affected by local conditions.
Conclusions: In data of the Forgotten Quadrant Survey, we find a good agreement between the total mass and velocity dispersion of the clouds derived from 12CO (1-0) and 13CO (1-0). This is likely because in the surveyed portion of the Galactic plane, the H2 column density is not particularly high, leading to a CO emission with a not very high optical depth. This mitigates the effects of the different line opacities between the two tracers on the derived physical parameters. This is a common feature in the outer Galaxy, but our result cannot be readily generalised to the entire Milky Way because regions with higher particle density could show a different behaviour.
Informazioni Pubbliche
Interstellar medium; Interstellar clouds; molecular gas; interstellar CO line emission; star formation; infrared astronomy; submillimeter astronomy
Il progetto coinvolge 13 ricercatori INAF di tre istituti: IAPS, OAA, IRA. Ci sono inoltre 2 ex post-doc di IAPS, ora all'estero. La PI è Milena Benedettini di IAPS.
Arizona Radio Observatory, Herschel Space Observatory
15. Team members, Informazioni generali
15. Personale INAF coinvolto
#
Nome
E-mail
Struttura
TI
Qualifica
Ruolo nel Progetto
FTE Impegnate (2022/2023/2024)
FTE Presunte (2022/2023/2024)
Extra
1
milena.benedettini
milena.benedettini@inaf.it
IAPS ROMA
Y
RICERCATORE
PI
X X X
X X X
X
2
maria.beltran
maria.beltran@inaf.it
O.A. ARCETRI
Y
RICERCATORE
co-I
X X X
X X X
X
3
jan.brand
brand@ira.inaf.it
IRA BOLOGNA
Y
PRIMO RICERCATORE
co-I
X X X
X X X
X
4
riccardo.cesaroni
riccardo.cesaroni@inaf.it
O.A. ARCETRI
Y
ASTRONOMO ASSOCIATO
co-I
X X X
X X X
X
5
davide.elia
davide.elia@iaps.inaf.it
IAPS ROMA
Y
RICERCATORE
co-I
X X X
X X X
X
6
francesco.fontani
francesco.fontani@inaf.it
O.A. ARCETRI
Y
RICERCATORE
co-I
X X X
X X X
X
7
sergio.molinari
sergio.molinari@inaf.it
IAPS ROMA
Y
DIRIGENTE DI RICERCA
co-I
X X X
X X X
X
8
luca.olmi
luca.olmi@inaf.it
O.A. ARCETRI
Y
PRIMO TECNOLOGO
co-I
X X X
X X X
X
9
stefano.pezzuto
stefano.pezzuto@inaf.it
IAPS ROMA
Y
RICERCATORE
co-I
X X X
X X X
X
10
kazi.rygl
kazi.rygl@inaf.it
IRA BOLOGNA
Y
RICERCATORE
co-I
X X X
X X X
X
11
eugenio.schisano
eugenio.schisano@inaf.it
IAPS ROMA
Y
RICERCATORE
co-I
X X X
X X X
X
12
leonardo.testi
leonardo.testi@inaf.it
O.A. ARCETRI
Y
DIRIGENTE DI RICERCA
co-I
X X X
X X X
X
13
alessio.traficante
alessio.traficante@inaf.it
IAPS ROMA
Y
RICERCATORE
co-I
X X X
X X X
X
14
scige.liu
scige.liu@inaf.it
IAPS ROMA
Y
C.T.E.R.
tecnico informatico
X X X
X X X
X
16. Personale Associato INAF coinvolto
#
Nome
E-mail
Struttura
TI
Qualifica
Ruolo nel Progetto
FTE Impegnate (2022/2023/2024)
FTE Presunte (2022/2023/2024)
Extra
21. Fondi a Sostegno Iniziativa
Il progetto è stato portato avanti essenzialmente da TI di INAF. Il finanziamento dedicato è stato ottenuto attraverso il progetto mainstream INAF del 2018.
