3C48: Evidence for two merger nuclei?

Melanie Krips University of Cologne

Andreas Eckart University of CologneRoberto Neri IRAM, FranceJens Zuther University of Cologne Dennis Downes IRAM, FranceJulia Scharwaechter University of Cologne

Submillimeter Astronomy in the era of the SMAJune 13, 2005

The Mice - Interacting galaxies NGC4676 @ Hubblesite.org

Stockton & Ridgeway 1991

Nucleus

3C48A

3C48

Pro Merger:

• " tail" towards NW (e.g. Stockton & Ridgeway 1991)

• bright host galaxy with large gas mass of 31010M (Scoville

et al. 1993; Wink et al. 1997)

• 2nd peak 3C48A in NIR (Zuther et al. 2004)

• extension of radio emission towards

3C48A (Feng et al. 2005)

Feng et al. 2005

core

counterjet

jet

3C48A

Nucleus

3C48A

3C48

Contra Merger:

• where is counter tail? like Antennae galaxies but seen from a different viewing angle (Scharwaechter et al. 2004)

• Nature of 3C48A? 2nd nucleus or interaction of the jet with ISM?

Feng et al. 2005

core

counterjet

jet

3C48A

3C48

New IRAM PdBI Observations (~1-2"):(Krips et al., accept. at A&A)

• continumm: 3.5 & 1.2mm• line: 12CO(1-0) (merged with Wink et al. 1997)

1.2mm & 3.5mm continuum

1.2mm continuum emission1.2mm continuum emission

3C48

Results (continuum):

• 1st map of continuum at 1.2mm• in very good agreement with radio maps

MERLIN 1.6GHz (18cm)1.2mm continuum emission

Feng et al. 2005

QSO

jet

3C48A

1.2mm continuum emission

3C48

Continuum model:

• 2 Gaussian model is not enough: residuum noise 3 Gaussian model fits much better (4)

3C48

Feng et al. 2005

new PdBI data

Results (12CO(1-0)):

• consistent with Wink et al. 1997 and Scoville et al. 1993• extended emission• total molecular gas mass: 1-61010M

Stockton & Ridgeway 1991

CO(1-0)

3C48

3 different lines?

3C48

two different positions!

3C48

3C48Molecular gas masses: 3C48A 1.0-3.61010M QSO-blue 0.2-0.91010M QSO-red 0.2-0.91010M

3C48A has largest gas mass!!!

one component

3C48A

QSO

CO-disks

3C48

Outlook• still need further observations• extended PdBI to separate the 2 CO systems• SMA to reveal further the non-thermal and/or thermal continuum emission at higher frequencies