1. Star Formation/ISM with Herschel
Malcolm Walmsley (Arcetri)
Floris van der Tak (MPIfR,Bonn)
Dusty04, Paris, Oct

2. Star Forming Regions are complex
Such as DR21 at roughly 3 Kpc (Marston et al. IRAC)
Dusty04, Paris, Oct

3. Fundamental steps forward with Herschel
PACS : Maps of star forming regions in continuum and OI 63 micron line
SPIRE : Maps on the large scale (eg of galactic plane, see Molinari HIGAL poster)
HIFI : Water and detailed kinematics of star forming regions
Dusty04, Paris, Oct

4. Why PACS is so important
High spatial resolution at the max. of the SED of most star forming regions (roughly 10 arc seconds or 0.1 pc at 3 kpc). This implies :
A) The capacity to separate the main sources of luminosity
B) The capacity to make maps with similar resolution to that available in the mm-submm
C) Basis for models at all wavelengths
For example, following comparison of Serpens as seen today at 3mm and as “expected” with PACS
Dusty04, Paris, Oct

5. Serpens at 3mm and 100 microns (Testi priv.comm)
Dusty04, Paris, Oct

6. At different wavelengths, different energy sources
It is often unclear where the main energy source is. For example HMPOs with embedded protostars as in IRAS (Fontani et al., Molinari et al.)
ISOCAM (left) and VLA 3cm (right) show that early B stars external to molecular core influence energetics
Dusty04, Paris, Oct

7. The SED is very sensitive to inclination
.... But only at short wavelengths (less than 100 mu)
[From Van Dishoeck , ARAA 2004]
Dusty04, Paris, Oct
[Whitney et al. 2004]

8. OI line mapping
HH 46-47
Will be fundamental for measuring outflow rate (see Ceccarelli et al. for OI with KAO)
Important also for PDRs
Distinguishing between them requires PACS resolution
[SPITZER: Noriega-Crespo e t al. 2004]
Dusty04, Paris, Oct

9. Water may be key to kinematics
Modeling it will be a challenge. Take for example our best guess at GL2591 (van der Tak)
Dusty04, Paris, Oct

10. The youngest objects have most water
In particular, water seems to be present in Class 0 envelopes and outflows
[ODIN: Hjalmarson et al. 2003]
[ISO: Nisini et al. 2000, Benedettini et al. 2003]
Dusty04, Paris, Oct

11. Present Models are simplistic
But suffice to explain presently available data from ODIN, SWAS, and ISO
Dusty04, Paris, Oct

12. A lesson from the above models
The HIFI Band 6 (high freq) lines tend to be in absorption against the continuum
These transitions should tell us about the kinematics along the line-of-sight to the protostar
The low freq water lines will tell us about the extended outflow (HH Objects)
Dusty04, Paris, Oct

13. Then there are the PDRs
Finding out ( perhaps from OH) just where ice evaporates in PDRs could be very fundamental
Then there will be new species (see Fuente et al.)
Dusty04, Paris, Oct
[From Van Dishoeck, ARAA 2004]

14. Conclusions
Combining PACS with HIFI is the best strategy for understanding protostars
But history tells us that the future revels
in the unexpected ! Spectral scans in the
THz range may provide the surprise ...
Dusty04, Paris, Oct