star formation/ism with herschel

Dusty04, Paris, Oct. 27-29 2004

Star Star Formation/ISM Formation/ISM with Herschelwith HerschelMalcolm Walmsley (Arcetri)Malcolm Walmsley (Arcetri)

Floris van der Tak Floris van der Tak (MPIfR,Bonn)(MPIfR,Bonn)


Star Forming Regions are Star Forming Regions are complexcomplex

Such as DR21 at roughly 3 Kpc Such as DR21 at roughly 3 Kpc (Marston et al. IRAC)(Marston et al. IRAC)


Fundamental steps forward Fundamental steps forward with Herschelwith Herschel

PACS : Maps of star forming regions PACS : Maps of star forming regions in continuum and OI 63 micron linein continuum and OI 63 micron line

SPIRE : Maps on the large scale (eg of SPIRE : Maps on the large scale (eg of galactic plane, see Molinari HIGAL galactic plane, see Molinari HIGAL poster)poster)

HIFI : Water and detailed kinematics HIFI : Water and detailed kinematics of star forming regionsof star forming regions


Why PACS is so Why PACS is so importantimportant

High spatial resolution at the max. of the High spatial resolution at the max. of the SED of most star forming regions (roughly 10 SED of most star forming regions (roughly 10 arc seconds or 0.1 pc at 3 kpc). This implies :arc seconds or 0.1 pc at 3 kpc). This implies :

A) The capacity to separate the main sources of A) The capacity to separate the main sources of luminosityluminosity

B) The capacity to make maps with similar B) The capacity to make maps with similar resolution to that available in the mm-submmresolution to that available in the mm-submm

C) Basis for models at all wavelengthsC) Basis for models at all wavelengths

For example, following comparison of For example, following comparison of Serpens as seen today at 3mm and as Serpens as seen today at 3mm and as “expected” with PACS“expected” with PACS


Serpens at 3mm and 100 Serpens at 3mm and 100 microns (Testi priv.comm)microns (Testi priv.comm)

Leonardo Testi, An HSO Survey of Nearby Star Forming Regions, Garching28 J anuary 2003

An HSO Survey of Nearby SFR

I FSI : P. Saraceno

M. Benedettini, A. di Giorgio, S. Molinari, S. Pezzuto, S. VitiArcetri: L. Testi, P. Caselli

OVRO 3mm

PACS m


At different wavelengths, At different wavelengths, different energy sourcesdifferent energy sources

It is often unclear where the main energy source It is often unclear where the main energy source is. For example HMPOs with embedded is. For example HMPOs with embedded protostars as in IRAS23889 (Fontani et al., protostars as in IRAS23889 (Fontani et al., Molinari et al.)Molinari et al.)

ISOCAM (left) and VLA 3cm (right) show that ISOCAM (left) and VLA 3cm (right) show that early B stars external to molecular core influence early B stars external to molecular core influence energeticsenergetics


The SED is very sensitive to The SED is very sensitive to inclinationinclination

.... But only at short wavelengths (less .... But only at short wavelengths (less than 100 mu)than 100 mu)

[From Van Dishoeck , ARAA 2004]

[Whitney et al. 2004]


OI line mappingOI line mapping Will be fundamental for Will be fundamental for

measuring outflow rate measuring outflow rate (see Ceccarelli et al. (see Ceccarelli et al. for OI with KAO)for OI with KAO)

Important also for Important also for PDRsPDRs

Distinguishing between Distinguishing between them requires PACS them requires PACS resolutionresolution

[SPITZER: Noriega-Crespo e t al. 2004]

HH 46-47


Water may be key to Water may be key to kinematicskinematics

Modeling it will be a challenge. Modeling it will be a challenge. Take for example our best guess at Take for example our best guess at GL2591 (van der Tak)GL2591 (van der Tak)


The youngest objects have The youngest objects have most watermost water

In particular, water seems to be In particular, water seems to be present in Class 0 envelopes and present in Class 0 envelopes and outflowsoutflows

[ODIN: Hjalmarson et al. 2003]

[ISO: Nisini et al. 2000, Benedettini et al. 2003]


Present Models are Present Models are simplisticsimplistic

But suffice to explain presently But suffice to explain presently available data from ODIN, SWAS, available data from ODIN, SWAS, and ISOand ISO


A lesson from the above A lesson from the above modelsmodels

The HIFI Band 6 (high freq) lines tend to The HIFI Band 6 (high freq) lines tend to be in absorption against the continuumbe in absorption against the continuum

These transitions should tell us about the These transitions should tell us about the kinematics along the line-of-sight to the kinematics along the line-of-sight to the protostarprotostar

The low freq water lines will tell us about The low freq water lines will tell us about the extended outflow (HH Objects)the extended outflow (HH Objects)


Then there are the PDRsThen there are the PDRs

Finding out ( perhaps from OH) just Finding out ( perhaps from OH) just where ice evaporates in PDRs could where ice evaporates in PDRs could be very fundamentalbe very fundamental

Then there will be new species (see Then there will be new species (see Fuente et al.)Fuente et al.)

[From Van Dishoeck, ARAA 2004]


ConclusionsConclusions

Combining PACS with HIFI is the best Combining PACS with HIFI is the best strategy for understanding protostarsstrategy for understanding protostars

But history tells us that the future But history tells us that the future revelsrevels

in the unexpected ! Spectral scans in in the unexpected ! Spectral scans in thethe

THz range may provide the surprise ...THz range may provide the surprise ...

star formation/ism with herschel

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