20” s. molinari – inaf/ifsi, rome hi-gal team ifsi - arcetri - univ. rome 1/2 - univ. lecce...
TRANSCRIPT
![Page 1: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/1.jpg)
20”
S. Molinari – INAF/IFSI, RomeHi-GAL team
IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts - Liverpool - Cardiff - UCL (UK), IPAC/SSC/JPL - Univ. Colorado - CfA (USA), Toronto - Calgary - U. Laval (Canada), MPIfR -
(Germany)et al.
Hi-GALThe Herschel infrared Galactic Plane Survey
Hi-GAL composite 47° > l > 36°
![Page 2: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/2.jpg)
Hi-GalA Herschel Key-Project for the Far-IR mapping of the inner
Galactic Plane• -60°<l<60° - |b| <1°, i.e.
the GLIMPSE and MIPSGAL areas
• 5 bands 70-500m imaging using PACS and SPIRE in Parallel Mode with crossed-rasters
• Area already surveyed in continuum and spectroscopy over few wavelength decades
Galaxy-wide Census, Luminosity, Mass and SED of dust structures
at all scales from massive YSOs to Spiral
Arms
![Page 3: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/3.jpg)
Hi-GALThe Herschel infrared Galactic Plane Survey
• The High-Mass Star Formation Timeline• Measure the star formation rate and history Galaxy-wide • Cold dust in the Galactic Plane and the Formation of Molecular
Clouds• Understanding star formation laws and the nature of thresholds as
a function of ISM properties across a full range of galactocentric radii metallicity and environmental conditions
• Determining the relative importance of global vs local, spontaneous vs triggering, agents that give rise to star formation.
• Build bottom-up recipes and prescriptions useful for Xgal science20”
Toward a Predictive Global Model of Galactic Star Formation
-70°< l < 70° |b|<1° - 70/160/250/350/500m – 343 hours
![Page 4: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/4.jpg)
Hi-GAL 70/160/350 Composite – Molinari+ 10
W43
Motte, Schilke & Lis 2003PACS 160
The black circle is the ALMA Band 9 primary beam !!
Herschel is crucial for ALMA
The black circle is the ALMA Band 9 primary beam !!
Herschel is crucial for ALMA
Bally+ 10
G29.96-0.02 Beuther et al. 2007
1”
![Page 5: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/5.jpg)
A Mass-Size power-law with exponent 1.33 is found to discriminate structures on the basis of their ability to form massive stars(Kauffmann et al. 2010)
The majority of sources are dense clumps which should be able to form M* > 10 M stars.
Nature of the compact sources
![Page 6: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/6.jpg)
Nature of the compact sources
M=M J
The majority of the detected cores are gravitationally
supercritical
Jeans conditions for gravitational instability
€
MJ (MΘ) =T
10K
⎛
⎝ ⎜
⎞
⎠ ⎟3
2
⋅nH2
104cm−3
⎛
⎝ ⎜
⎞
⎠ ⎟
− 12 Mean Clumps
Temperature
![Page 7: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/7.jpg)
Nature of the compact sources
ZAMS
ACCRETION
Krumholz & McKee (2008)L/M due to accretion onto low-mass protostars, at given SFR and IMF
L/M where accretion radiation is sufficient to halt fragmentation of low-mass cores
≈1 g cm-2
A significant fraction of the clumps should be already forming high-mass protostars (M≥10M)
Molinari+ 2008
![Page 8: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/8.jpg)
However…
The actual core surface density is significantly below what the Krumholz & McKee 08 theory predicts (Elia+ 10)
Other agents supporting against fragmentation, other than accretion radiation from low-mass protostars, must be at work.
Magnetic field is a possibility (Commerçon+ 10, although in a slightly different context)
![Page 9: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/9.jpg)
l = 59° - SPIRE 250
The Filamentary Nature of Star FormationMolinari+ 10
![Page 10: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/10.jpg)
Filament and compact objects
• Compact sources are mostly found associated to filamentary structure
• There is no apparent correlation between mass of compact sources and the column density of the hosting filament
• There is a strong suggestion for a threshold effect around AV≈1 Hollenbach et al. 1991
![Page 11: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/11.jpg)
Filament fragmentationHeitsch et al. 2008
Local filaments density
Preliminary filament section measurements in the l=59° region give values between 0.5 and 1pc.
Local filaments temperature Conclusion: filaments form from
diffuse ISM and grow in column density until at AV≈1 heating and cooling go out of balance. Gravitational instability comes in and high-density fragments start to appear.
![Page 12: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/12.jpg)
Is B important in filament fragmentation ?
Filaments hosting compact sources span a N(H2) range which is compatible with structures losing magnetic
support and starting to collapse
Filaments hosting compact sources span a N(H2) range which is compatible with structures losing magnetic
support and starting to collapse
M/=1
Fiege & Pudritz 2000
![Page 13: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/13.jpg)
Census of Filaments (Schisano+, in prep.)
Automated Filament Detection
• Complete catalogue of filaments• Statistics of filaments length and cross-size• Multi-scale analysis to obtain hierarchical information
![Page 14: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/14.jpg)
Properties of filaments and their relationship to cores/clumps
(Schisano+, in prep.)
Cross-matching to compact source catalogues to:• subtract flux of compact sources from the integral under the RoIs• Obtain statistics of filament/clump associations
• Subtract background from nearby regions• Fit greybodies to measure Masses and Temperatures• Cross-match to molecular line databases to (e.g. GRS) to obtain velocity dispersion: virial masses, confirm physical nature, …
![Page 15: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/15.jpg)
The Earliest Stages of High-Mass SF : Shadows…
PACS 70
PACS 160
SPIRE 250
and Lights
Peretto+ 10D=3kpc
D=12 kpc
• ALMA will allow comprehensive studies of SF regions over the entire Galaxy, “unlocking” access to the same level of detail we currently have for nearest regions• Hi-GAL will constitute the essential input database for statistically significant studies of the earliest stages of massive SF and the lifetime of pre-stellar phase• ALMA will enable us to
• resolve the Jeans length Galaxy-wide• address the early fragmentation of clumps and filaments across a variety of Galactocentric distances, metallicities and environmental conditions (morphology, chemistry and dynamics)
![Page 16: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/16.jpg)
Triggered Star Formation(5’x5’ field) – Zavagno+ 10
![Page 17: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/17.jpg)
300° 298°
Hi-GAL coming along…SPIRE 250m
![Page 18: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/18.jpg)
The future is bright
The outer Galaxy is unique to complete a large and otherwise uncharted parameters space:
• Get SFR, SFE, SFH vs R. Different SF thresholds ? Different S-K law ?
• Is the path from clouds to protostars the same ? Different timescales ? Different agents ?
• Build the bottom-up recipe of an entire Galaxy
ALM
A
avoi
dan
ce
(<
+40°)
ALM
A
avoi
dan
ce
(<
+40°)
The HOTAC granted 278 hours in OT1 to cover another 120° longitude range centered on the anti-center. The greater Hi-GAL now covers 520 sq. deg.
Most of it will be accessible by ALMA !!
![Page 19: 20” S. Molinari – INAF/IFSI, Rome Hi-GAL team IFSI - Arcetri - Univ. Rome 1/2 - Univ. Lecce (Italy), CESR - OAMP - IAS - Saclay (France), RAL - Herts -](https://reader036.vdocuments.us/reader036/viewer/2022062515/56649ce65503460f949b3a74/html5/thumbnails/19.jpg)
The future is bright
Hi-GAL is a goldmine for the Community to peruse !!
For your science….to plan ALMA science….to maximize ALMA science
Data are already public as they come out of the standard pipeline
The Hi-GAL Consortium will start incremental releases of high-quality products (images and catalogues) 6 months after the data
taking of 1st survey
The SDP tiles enhanced products will be released shortly
ALM
A
avoi
dan
ce
(<
+40°)
ALM
A
avoi
dan
ce
(<
+40°)