star formation: from herschel to...

Star formation: from Herschel to SPICA

1 C.Ceccarelli -‐ Rome, Feb 2013

Cecilia Ceccarelli Ins8tut de Planétologie et d’Astrophysique de Grenoble

Some related reviews: Van Dishoeck 2004, ARAA; Nisini et al. 2005, SSR; Ceccarelli et al. 2007, PPV; Melnick 2009, ASP; Evans 2011, IAU; Caselli & Ceccarelli 2012 AAR

FROM A DIFFUSE CLOUD TO A SUN + PLANETARY SYSTEM FROM ATOMS & SIMPLE MOLECULES TO LIFE

1-‐ PRE-‐STELLAR PHASE: cold and dense gas FORMATION OF SIMPLE MOLECULES

2-‐ PROTOSTELLAR PHASE: collapsing, warm dense gas FORMATION OF COMPLEX MOLECULES

3-‐ PROTOPLANETARY DISK PHASE: cold and warm dense gas SIMPLE & COMPLEX MOLECULES

4-‐ PLANETESIMALS FORMATION : grains agglomera8on

5-‐ PLANETS FORMATION AND THE “COMETS/ASTEROIDES RAIN” CONSERVATION AND DELIVERY OF OLD MOLECULES + LIFE


OUTLINE 1.  The census 2.  The structure 3.  The chemistry

4.  The oublow

C.Ceccarelli -‐ Rome, Feb 2013 4

From ISO, SPITZER, AKARI… HERSCHEL to SPICA: the heritage and open ques8ons

OUTLINE

1.  The census 2.  The structure 3.  The chemistry

4.  The oublow


THE CENSUS

C.Ceccarelli -‐ Rome, Feb 2013 6 1. The census

IN ORDER TO STUDY THE STRUCTURE AND EVOLUTION OF PROTOSTARS WE NEED TO HAVE THE OBJECTS TO STUDY: THE LARGEST POSSIBLE SAMPLE COVERING THE LARGEST POSSIBLE ENVIRONMENT CONDITIONS, POSITIONS IN THE GALAXY, AND EVOLUTIONARY STATUS.

WE NEED A CENSUS OF THE PROTOSTARS IN OUR GALAXY

THE CENSUS

C.Ceccarelli -‐ Rome, Feb 2013 7 1. The census

IRAS: THE START OF THE STORY WITH THE FIRST CATALOGUE LIMITED SENSITIVITY, SPATIAL RESOLUTION AND FREQUENCY COVERAGE

DEFINITION OF CLASS I, II, III GROUND BASED SURVEYS IN THE IR AND mm

INTRODUCTION OF CLASS 0 (and CLASS –I /prestellar cores)

ISO: ISOCAM MAPPED IN THE MIR (7 and 14 µm) A FEW deg2 OF NEARBY STAR-‐FORMING REGIONS

SPITZER: MAPPED 15.5 deg2 OF FIVE LARGE NEARBY MOLECULAR CLOUDS DISCOVERY OF THE VELLOS

HERSCHEL: FULL MAP OF THE GALACTIC PLANE AND OF THE GOULD BELT STAR FORMATION REGIONS  THE UBIQUITY OF FILAMENTS AND THEIR IMPORTANCE (Sergio Molinari’s talk)

THE SPITZER SURVEY of the Core to Disk (c2d) LP (Evans et al. 2003)

C.Ceccarelli -‐ ATROMOL IPAG 8 1. The census

o  RIVISITED LIFETIMES: ≈2Myr Class II, ≈0.5Myr Class I, ≈0.16-‐0.043 Class 0 o  CONFIRMATION OF THE “LUMINOSITY PROBLEM”NON-‐STEADY ACCRETION?

RESULTS

Evans et al. 2009

III

I II

Flat

THE SPITZER SURVEY of the Core to Disk (c2d) LP (Evans et al. 2003)

C.Ceccarelli -‐ ATROMOL IPAG 9 1. The census

o  RIVISITED LIFETIMES: ≈2Myr Class II, ≈0.5Myr Class I, ≈0.16-‐0.043 Class 0 o  CONFIRMATION OF THE “LUMINOSITY PROBLEM”NON-‐STEADY ACCRETION?

RESULTS

Evans et al. 2009

III

I II

Flat

SPICA, A SUPER SPITZER/AKARI, WILL PROVIDE A HUGE DATASET AND LIKELY A NEW AND COMPLETE VIEW OF

STAR FORMATION IN OUR GALAXY

OUTLINE


4.  The oublow


THE STRUCTURE OF PROTOSTARS

C.Ceccarelli -‐ Rome, Feb 2013 11 2. The structure

WHY: WE WANT TO KNOW WHAT ARE THE DENSITY AND TEMPERATURE PROFILES TO UNDERSTAND WHAT ARE THE ACTORS/PROCESSES ENTERING THE STAR FORMATION PROCESS

OBSERVED PROFILES

MODEL PREDICTIONS

How important are the magne8c fields, the turbulence? What did start the collapse?...

THE STRUCTURE OF THE PROTOSTAR


DERIVATION OF THE DENSITY AND TEMPERATURES PROFILES:

1) Dust density and temperature profiles " " con8nuum spectral energy distribu8on + emission maps

2) Gas density and temperature profiles line spectra (emission + absorp8on)

OFTEN, SPHERICAL SYMMETRY ASSUMED, SOMETIMES 2-‐D, WITH THE ADDITION OF MORE PARAMETERS TO FIT

Dust temperature and density profiles


Shoier et a

l. 2002

Schoier et al. 2007, Crim

ier et al. 2010

Crim

ier et al. 2010

Spitzer ISO via dust radia8ve transfer modeling

e.g. DUSTY (Ivezik & Elitzur 1997, Withney et a. 2003; Robitaille et al. 2007, 2011 )

Caselli & Ceccarelli 2012



Shoier et a

l. 2002

Schoier et al. 2007, Crim

ier et al. 2010

Crim

ier et al. 2010

Spitzer ISO via dust radia8ve transfer modeling

e.g. DUSTY (Ivezik & Elitzur 1997, Withney et a. 2003; Robitaille et al. 2007, 2011 )

Caselli & Ceccarelli 2012

SPICA: MAPS AND SED OF WEAK SOURCES



Jorgen

sen et a

l. 2002

RESULTS Most of the density profiles of Class 0 sources are consistent with the free-‐fall structure, within the error bars, with a few excep8ons.

Class 0

free-‐fall

QUESTIONS: So far only the brightest objects have been modeled: what is the profile of low luminosity objects? Will they form ~1 Mo or << Mo stars ? Why, when and how? => Study of hydrosta8c cores?



THE SPITZER AT 20-‐60mic OBSERVATIONS HAVE RAISED THE QUESTION WHETHER LARGE CAVITIES ARE PRESENT IN SOME PROTOSTELLAR ENVELOPES (e.g. Schoier et al. 2004, Jorgensen et al. 2005)

BUT IS THE COW REALLY SPHERICAL?

No cavity With a cavity

Crim

ier et al. 2010

THE CAVITY MODEL FITS THE SPITZER DATA BUT NOT THE LARGE SCALE MAPS (e.g Crimier et al. 2010)

..???.... IS THE NIR DUE TO A

DISK?



SPICA WITH ITS 2-‐ORDERS OF MAG BETTER SENSITIVITY WILL HAVE CERTAINLY A KEY ROLE TO PLAY HERE:

1.  STUDY OF NEARBY LOW LUMINOSITY PROTOSTARS: HYDROSTATIC CORES?

2.  STUDY OF DISTANT LOW-‐MASS PROTOSTARS: IS STAR FORMATION IN DIFFERENT ENVIRONMENT MUCH DIFFERENT TOO?

3.  STUDY OF THE GEOMETRY (COMPLEMENTARY TO ALMA STUDIES): WHY NIR IS BRIGHT IN MANY EMBEDDED PROTOSTARS?

OUTLINE


4.  The oublow


THE CHEMICAL COMPOSITION

C.Ceccarelli -‐ Rome, Feb 2013 19 3. The chemistry

WHY: WE WANT TO KNOW WHAT IS THE CHEMICAL COMPOSITION ACROSS THE ENVELOPE TO UNDERSTAND THE PHYSICAL STATUS OF THE GAS AND THE HISTORY OF THE PROTOSTAR

OBSERVED SPECIES

MODEL PREDICTIONS

How is the gas cooled? What is the ioniza8on? Why? Which species are in the gas phase, which are frozen? Why? What is the age of the protostar? What is the molecular complexity during the star forma8on process?...

C.Ceccarelli -‐ ATROMOL IPAG 20

BEFORE THE ONSET OF THE COLLAPSE, THE CONDITIONS (LOW TEMP AND HIGH DENS) ARE PROPITIUS TO THE FORMATION OF ICED DUST MANTLES

1)  MOLECULES like CO FREEZE OUT ONTO THE DUST GRAINS

2)  O, N, CO HYDROGENATION ON GRAINS FORM H2O, NH3, H2CO, CH3OH…

Caselli et al. 2012 PRE-‐COLLAPSE PHASE AND THE ICED DUST

MANTLES FORMATION

3. The prestellar phase

COMPOSITION OF THE GRAIN MANTLES

C.Ceccarelli -‐ ATROMOL IPAG 21 3. The prestellar phase

Whi

ttet

et

al. 2

010

ISO started the revolu8on, by providing the composi8on of the ices in massive protostars

SPITZER and AKARI provided the composi8on of (bright) low mass protostars

Pontoppidan 2006

COMPOSITION OF THE GRAIN MANTLES

C.Ceccarelli -‐ ATROMOL IPAG 22 3. The prestellar phase

SPICA WILL PERMIT TO STUDY THE ICE COMPOSITION AND GRAIN MINERALOGY

IN A HUGE SAMPLE OF PROTOSTARS (AND DISKS)

WATER: THE DOMINANT COOLANT IN THE INNERMOST WARM REGIONS (HOT CORES/CORINOS)


MODELS PREDICT THAT THE GAS MAY BE THERMALLY DECOUPLED BY THE DUST AT THE BORDER AND IN THE INNER REGION (WHERE TDUST>TICE-‐SUBLIMATION) OF THE ENVELOPE, DEPENDING ON THE WATER ABUNDANCE IN THE INNER REGIONS.

Crimier et al. 2010

QUESTIONS: Does the thermal decoupling influences the dynamical collapse? How does it depend on the water abundance?

Gas temperature profile


HERSCHEL IS PROVIDING A MINE OF NEW DATA IN LOW AND HIGH MASS PROTOSTARS

THE ABUNDANCE MEASURED IN THE HOT CORES/CORINOS SEEMS TO BE <10-‐4 (=THE ABUNDANCE OF ICED WATER):

WHY?

Couten

s et al. 2012

Empreich8nger et al. 2013

Gas temperature profile


HERSCHEL IS PROVIDING A MINE OF NEW DATA IN LOW AND HIGH MASS PROTOSTARS

SPICA WILL ALLOW TO STUDY A LARGE SAMPLE, EVEN THOUGH IT WILL NOT HAVE THE SPECTRAL RESOLUTION, PROVIDING A LARGE NUMBER OF H2O LINES @38-‐210µm

Couten

s et al. 2012

Empreich8nger et al. 2013


ISO TO HERSCHEL STUDIES PROVIDE A COMPLEX PICTURE OF THE STRUCTURE OF LOW-‐MASS PROTOSTARS:

1. COLD ENVELOPE 2. HOT CORINO 3. INNER SHOCKS 4. UV ILLUMINATED GAS 5. INNER DISK

ADAPTED FROM van Dishoeck 2004, ARAA


1. COLD ENVELOPE 2. HOT CORINO 3. INNER SHOCKS 4. UV ILLUMINATED GAS 5. INNER DISK

SPICA WILL PLAY A MAJOR ROLE IN PROVIDING OBSERVATION OF LINES FROM HIGH-‐J CO and HIGH LYING

H2O TRANSITIONS AS WELL AS FROM MANY OTHER ABUNDANT HYDRIDES LIKE NH3, OH, HCO+, HCN…

THE CHEMICAL COMPOSITION


THE HERSCHEL UNBIASED SPECTRAL SURVEYS ARE HELPING US IN UNDERSTANDING THE CHEMICAL COMPOSITION OF HIGH AND LOW MASS PROTOSTARS. THEY WILL ALSO GUIDE THE NEW SPICA-‐SAFARI OBSERVATIONS TO DO.

OVERVIEW of 555-‐635GHz SPECTRA

THE CHESS HERSCHEL KEY PROGRAM Ceccarelli et al. 2010

The large majority of the lines have upper level energy >100K => they originate in warm/hot gas. Excep8ons: fundamental lines of some hydrides, H2O, NH3, HCl, and D2O => from cold gas.

LUM


OVERVIEW of 555-‐635GHz SPECTRA

Source Luminosity (Lo)

No Lines No Species

L1157-‐B1 -‐ 27 8

IRAS16293 21 86 22

OMC2-‐FIR4 1x103 71 17

AFGL2591 2x104 16 11

NGC6334I 2x105 558 26

A bit of sta8s8cs

No. Species

L1157-‐B1

IRAS16293

OMC2-‐FIR4

AFGL2591

NGC6334

No. Lines

The number of lines in a spectrum is NOT a unique criterion for chemical richness


OVERVIEW of THE NGC6334I SPECTRA

THE NUMBER OF LINES DECREASES WITH INCREASING FREQUENCY, BECAUSE OF

THE LINES EXCITATION AND DUST ABSORPTION C.Ceccarelli -‐ Rome, Feb 2013 31

SPICA-‐SAFARI

HIGH MASS = HIGH ABSORPTION


!!! SPICA-‐SAFARI WILL BE A GREAT INSTRUMENT TO STUDY LOW-‐MASS BUT NOT NECESSARELY HIGH-‐MASS

STAR FORMING REGIONS 3. The chemistry

Ceccarelli et al. 2002

ISO: NH3 towards SgrB2 Herschel: H3O towards NGC6334I

Empreic8nger et a

l. 2013

OUTLINE


4.  The oublow


THE OUTFLOW

C.Ceccarelli -‐ Rome, Feb 2013 34 5. The oublow

OBSERVED PROPRIETIES

MODEL PREDICTIONS

How much energy is injected in the ISM? How? What kind of shocks are created? How are they cooled? How are they generated? Jets/wide winds? What species are injected in the ISM from those shocks?

WHY: OUTFLOWS ARE UBIQUITOUS AND A KEY INGREDIENT IN THE STAR FORMATION PROCESS: THEY GET RID OF THE ANGULAR MOMENTUM, DISSIPATE THE PLACENTAL ENVELOPE, DESTROY THE PARENTAL CLOUD INJECTING TURBULENCE IN ISM

THE OUTFLOW


MOLECULAR SHOCKS: EXPECTED WATER FUNTAINS

C-‐shocks (Kaufman & Neufeld 1996) J-‐shocks (Hollenbach & mcKee 1979)

THE OUTFLOW


OBSERVATIONS OF WATER IN MOLECULAR OUTFLOWS OBTAINED WITH ISO (many lines, poor spectral resolu8on ≈ 200), SWAS AND ODIN (fundamental o-‐H2O line @557GHz, high spectral resolu8on ≈ 106, poor spa8al resolu8on ≈ 1.5-‐4’)

x(o-‐H2O) ≈ 10-‐7-‐10-‐5

SWAS

Liseau et a

l. 1996

ISO

x(H2O) ≈ 10-‐5

Bergin et al.2003

YES, WATER IS ABUNDANT INDEED…BUT NOT SO MUCH AS EXPECTED

THE OUTFLOW


ODIN

Bjerkeli et al.2009

YES, WATER IS ABUNDANT INDEED… BUT NOT SO MUCH AS EXPECTED

(ISO: Nisini et al. 2002, SWAS: Franklin et 2008, ODIN: Bjerkeli et al. 2009…)

THE WATER ABUNDANCE INCREASES WITH THE GAS TEMPERATURE/MAX VELOCITY in rough agreement with predic8ons for non-‐dissocia8ve C-‐shocks

THE OUTFLOW


HOW MANY COMPONENTS? HOW MANY SHOCKS?

H2 AND H2O EMISSION OBSERVED BY ISO/SPITZER/ AKARI+HERSCHEL TESTIFIES OF NON DISSOCIATIVE SHOCKS WHILE OI EMISSION OBSERVED BY KAO/ISO TESTIFIES OF DISSOCIATIVE SHOCKS

Lefloch et al.2003

Nisini et a

l. 2010

NEW HIFI-‐HERSCHEL OBSERVATIONS SHOW THE PRESENCE OF 3 COMPONENTS, WHOSE RELATIVE CONTRIBUTION CHANGES WITH THE ENERGY OF THE TRANSITION

Lefloch et al.2012

THE OUTFLOW


HOW MANY COMPONENTS? HOW MANY SHOCKS?

H2 AND H2O EMISSION OBSERVED BY ISO/SPITZER/ AKARI+HERSCHEL TESTIFIES OF NON DISSOCIATIVE SHOCKS WHILE OI EMISSION OBSERVED BY KAO/ISO TESTIFIES OF DISSOCIATIVE SHOCKS

Lefloch et al.2003

Nisini et a

l. 2010

NEW HIFI-‐HERSCHEL OBSERVATIONS SHOW THE PRESENCE OF 3 COMPONENTS, WHOSE RELATIVE CONTRIBUTION CHANGES WITH THE ENERGY OF THE TRANSITION

Lefloch et al.2012

More in Nisini’s talk

SPICA WILL PROVIDE A HUGLY LARGER SET OF DATA FOR MAPS OF WARM GAS IN MOLECULAR SHOCKS HELPING IN UNDERSTANDING THE FEEDBACK OF STAR FORMATION

CONCLUSIONS



4.  The oublow

HERSCHEL IS HELPING TO SOLVE THE SEVERAL OPEN QUESTIONS LEFT BY ITS PRECEDESSORS AND MORE WILL COME IN THE COMING YEARS, BUT IT WILL NOT ANSWER ALL QUESTIONS: SPICA WILL BE GREATLY IMPROVE OUR UNDERSTANDING OF

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