INTERACTIVATION

AND

COSMOLOGY

Henri Reboul

GRAAL UMR 5024

AMT - L’HOSPITALET – 2-3 / 12 / 2005

Cosmological parametersCosmological parameterswith the with the

transparent universe transparent universe

z

m

z

m

Standard Rulers

z

m

Standard Rulers Standard Candles

Cosmological parameters with the Cosmological parameters with the transparent universetransparent universe

mmz z « classical » (cz « classical » (cz H Ho o d)d) : : Lemaître 1927, Lemaître 1927, Hubble, 1929, …) → HHubble, 1929, …) → Hoo

zz and angular-diameter distance : Tolman and angular-diameter distance : Tolman 1930, … Kellermann 1993, … → (q1930, … Kellermann 1993, … → (qoo))

mmzz and luminosity distance : Mineur 1933, and luminosity distance : Mineur 1933, Robertson 1938, … Riess et al 1998, Perlmutter Robertson 1938, … Riess et al 1998, Perlmutter et al 1999, … et al 1999, … ioio

def

PS : projected separation (length) at te

o : observed angular separation at to

zc

def

(ro negligible for z<3)

dm is the « metric » or « proper motion » distance

dA is the « angular diameter » distance : dA = dm / (1+zc)

dm = dm (Ho, io, zc)

dm-, dmo, dm+ for the 3 curvatures of space

BASICS

o

EdS

0.3 0.7

0.3 0.0

Some tried standard rulersSome tried standard rulers

Galaxies … (evolution)Galaxies … (evolution)Galaxy Clusters …(evolution)Galaxy Clusters …(evolution)

Radio-sources (Kellermann 1993, …) : qRadio-sources (Kellermann 1993, …) : qoo ? ?

Milliarcsecond radiosources (Gurvits et al 1999, Milliarcsecond radiosources (Gurvits et al 1999, Chen and Ratra 2003) : wide constraintsChen and Ratra 2003) : wide constraintsDouble-lobbed radio-sources (Guerra et al 2000, … Double-lobbed radio-sources (Guerra et al 2000, … Zhu and Fujimoto, 2004) : wide constraintsZhu and Fujimoto, 2004) : wide constraintsAcoustic peak at t z=0.35 in SDSS and in CMB Acoustic peak at t z=0.35 in SDSS and in CMB (Eisenstein 2005) !(Eisenstein 2005) !

« Interactivated » pairs« Interactivated » pairsas standard rulersas standard rulers

Pairs in interactionPairs in interactionActive because in interactionActive because in interactionActive : Starburst or AGNActive : Starburst or AGNCause of activation : gravitationCause of activation : gravitationCause of separation: gravitationCause of separation: gravitationPreferred linear separation (?) Preferred linear separation (?) Emission linesEmission linesNo (measuring) bias on No (measuring) bias on and z and z

PopulationsPopulations

Interactivated Pairs of Quasars or Seyfert ?Interactivated Pairs of Quasars or Seyfert ?

Interactivated Pairs of Starburst Galaxies ?Interactivated Pairs of Starburst Galaxies ?

2dFGRS release ….2dFGRS release ….

2dFGRS

2dFGRS

3239

Projected separation (concordance)

N (emission lines) > 2

N (emission lines) > 3

N (emission lines) > 4

N (emission lines) > 4 and v < 100 km/s

(Better efficiency of slow encounters

and rejection of optical pairs)

10’

B < 2

v < 75 km/s

N(em. Li) ≥ 5

Poisson 105 (0.7/h) kpc

Reboul & Cordoni , A&A in press

100 150 200 250

300 350 400 450

500 550

750

600 650

800750

Dubinski

MW/M31 encounter

Gravitation only

1st enc.

2nd enc.

merger

The Astrophysical Journal, 622:L9-L12, 2005 March 20© 2005. The American Astronomical Society. All rights reserved. Printed in U.S.A.

Springle & Hernquist 2005: gravitation and starburst

Two steps of starburst : first encounter and 2nd pre-merger

DELAYE & PEPIN , Montpellier (L1): simple modelisation for the first starburst with a Keplerian orbit between the 1st and 2nd pre-merger encounters and the SFR of Springel & Hernquist 2005

DELAYE & PEPIN, Montpellier (L1): fitting the masses and parameters of the Keplerian orbit (and the duration of starburst) to the distribution of PS of 2dFGRS interactivated galaxies candidates. Would seem to favour high masses and long starbursts …

Monte-CarloMonte-Carlo

PS – distribution: Poisson 134 (0,7/h) kpcPS – distribution: Poisson 134 (0,7/h) kpcZ – distribution : that of 2QZ (2dFQRS)Z – distribution : that of 2QZ (2dFQRS)Random orientationRandom orientation

4 sets of (4 sets of (mm, , ) : ) : (1.0, (1.0, 0.0) (0.3, 0.0) (0.3, 0.7) (0.1, 0.9)0.0) (0.3, 0.0) (0.3, 0.7) (0.1, 0.9) z synthetic samplesz synthetic samplesLevenberg-Marquardt inversion Levenberg-Marquardt inversion Retrieved Retrieved s (1s (1, 2, 2 bananas) bananas)

Reboul & Cordoni

Reboul & Cordoni , A&A in press

Random orientation

(angle on the line of sight)

cos is the uniform random variable on [0,1]

Real Separation RS : PS = RS sin

N pairs; dN pairs between and

Dispersion of data by unknown orientation is weak

Mean projection ratio : < sin >

Retrieved

s

with

1000 pairs

Reboul & Cordoni

EdS

Concordance

Retrieved

s

with

1000 pairs

1 and 2 contours

Reboul & Cordoni

A&A in press

EdS

C

How many pairs of Interactivating Galaxies ?

with

For a flat universe (and neglecting r):

How many Interactivated Pairs in the sky ?

Results (□ = square degree)

Local sample : 45 candidates in 1500□ for z < 0.11

fo 3000 Gpc-3

Deep sample : 80 / □ for z <3 if m = 3 (700 if m = 5)

More than 107 on the wole sky (if m>4)

Internal Sigmas on s versus N-pairs

1.

2. m

3. mor if k=0

Reboul & Cordoni A&A in press

N=1000

N= 100 000

CONCLUSIONS

Interactivation and cosmology

• No bias on the measure of separations : larger than 10 arcsec between well idientified nuclei of primary interactivating galaxies

• No bias on the measure of the redshift : strong emission-line objects

• Main Problem (with pair of primary starburst galaxies): faintness for spectroscopy (MB ~ - 19 for the mean of luminosities, ~ -21 for the brightest

i.e. m ~ -28 to ~ - 26 at z =3)

• Possibilities with brightest interactivated pairs : Sy ? QSOs ? Other ?