Download ppt - Crete, 1/24 Mapping the kinematics and stellar populations of E/S0s with SAURON Harald Kuntschner Crete, 12 th August 2004

Crete, 1/24

Mapping the kinematics and stellar Mapping the kinematics and stellar populations populations

of E/S0s with SAURON of E/S0s with SAURON

Harald KuntschnerHarald KuntschnerCrete, 12Crete, 12thth August 2004 August 2004

Crete, 2/24

OutlineOutline

• Introduction• The SAURON survey• Results from

– Kinematics – Stellar populations with focus on

environmental effects

• Conclusions

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The SAURON teamThe SAURON team

PIs: Bacon, Davies, de Zeeuw

COIs: Bureau, Cappellari, Emsellem, Falcón-Barroso, Krajnović, Kuntschner, McDermid, Peletier

plus associated members …

http://www.strw.leidenuniv.nl/sauron

Crete, 4/24

GalaxyGalaxyformationformation

• When and how do E/S0/Sa galaxies form?– What is the orbital make-up of E/S0s?– What is the average age and metal

content?– Origin of substructures; e.g. faint disks

in Es, decoupled cores, etc.– E S0 Sa transformations?– What is the relationship between global

properties and super-massive black holes ?

SAURON

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The SAURON projectThe SAURON project

• Systematic study of a representative sample of 48 nearby E/S0s and 24 Sa-type spirals – Wide field integral-field spectroscopy from

the ground (SAURON)– Central high spatial sampling integral-field

spectroscopy with OASIS/GMOS – HST imaging (and some STIS spectroscopy)– Large scale ground based imaging

de Zeeuw et al, 2002, MNRAS, 329, 513

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The sample selectionThe sample selection

• Uniformly covering the ellipticity vs MB plane• MB -18 mag (factor of 50 in luminosity)• 24 E, 24 S0, 24 Sa (each 12 cluster, 12 field)• cz < 3000 km/s• DEC: -6° < d < +64° and |b| 15°

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Why integral-field Why integral-field spectroscopy?spectroscopy?

Galaxy Image

Velocity field

Velocity curve

Integral field

Long slit

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Status of the SAURON surveyStatus of the SAURON survey

• Observations completed in April 2002– 8 runs on William Herschel Telescope (4m)– 35.5/56 clear nights

• ~200.000 independent galaxy spectra • All data homogeneously reduced• Analysis and interpretation ongoing

– 5 refereed papers in 2004 so far

Crete, 9/24

48 E/S0 – DSS images 48 E/S0 – DSS images Emsellem et al., 2004, MNRAS, 352, 721

Crete, 10/24

SAURON-classified rotatorsSAURON-classified rotators

S0

S0 S0

S0

S0 E

E

EE

E

E E

S0 S0

S0

S0

S0 S0 S0

S0

E

S0S0

S0

S0

S0

E S0

E

E S0

E E

S0

S0

S0

40% classified by RC3 as ellipticals

Crete, 11/24

SAURON-classified ellipticalsSAURON-classified ellipticals

EE

E

E

S0 E

EE

EE

E

E

General agreement with RC3

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Results from the kinematic mapsResults from the kinematic maps

• Two classes of early-type galaxies – Flattened rotating lenticulars (some with bars)– Triaxial ellipticals (many kinematically

decoupled components)

• Discontinuous transition

NGC 4660 NGC 4458

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Line-strength: Age, Z, [Mg/Fe]Line-strength: Age, Z, [Mg/Fe]

• Wavelength covers H, Fe5015, [OIII], Mgb & Fe5270• Lick/IDS index definitions (+ SAURON adjustments)• Indices + Models can be used to estimate luminosity

weighted age, Z and abundance ratios.

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Kinematics and line-StrengthsKinematics and line-Strengths

I

V

Mgb

Fe

NGC 4546 NGC 4570 NGC 4406 NGC 4365NGC 4660 NGC 4382 NGC 4374

N

E

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Stellar population modelsStellar population models

Vazdekis (1999) models atLick resolution (~8.4 Å FWHM) based on Jones (1999) library

[MgFe52]=(Mgb x Fe5270)^0.5

Goal:

Estimate the luminosity weighted age, metallicity and abundance ratios.

Crete, 16/24

Central Re/8 measurementsCentral Re/8 measurements

Traditional RC3morphologies

Mostly old Es

Weak evidence for young stellar populations in some field Es

S0s in all environs spread to younger ages

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Central Re/8 measurementsCentral Re/8 measurements

New “morphologies”based on 2-dim kinematics

7 triaxial Es in field

only 4 triaxial Es in cluster

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NGC 5198 (E; field)NGC 5198 (E; field)V Hβ [MgFe50]

Age map Z map

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NGC 4150 (S0; cluster)NGC 4150 (S0; cluster)V Hβ [MgFe50]

Age map Z map

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Age map Z map

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A bar in NGC 4570A bar in NGC 4570van den Bosch & Emsellem van den Bosch & Emsellem

(1998)(1998)Metal lines

Age map

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Age map Z map

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Statistics – young Statistics – young populationspopulations

• 19/48 (40%) of our sample show some evidence of “young” (<10Gyr) stellar populations in the central regions

• E cluster: 1/12• E field: 4/12 E total: 5/24

• S0 cluster: 7/12• S0 field: 7/12 S0 total:

14/24

Crete, 24/24

ConclusionsConclusions• SAURON provides 2-dim kinematics and line-strength for

48 nearby E/S0• Kinematics

– Many RC3 classified Es show strong rotation; we suggest new classification in triaxial Es and rotators

• Line-strength – Connection between ‘disk-like’ kinematics and

enhanced Mgb line-strength (not seen so clearly in Fe lines!)

– Evidence for secular, bar-driven evolution in S0s young pops rotation connection in some galaxies

– As many as 40% of E/S0 galaxies show signs of young stellar populations mostly in the central regions

• Only weak evidence for environmental effects in our sample