Starburst in Seyfert 2 Nuclei Starburst in Seyfert 2 Nuclei Qiusheng Gu Qiusheng Gu (NJU, China)(NJU, China) Jorge Melnick Jorge Melnick (ESO, Chile) (ESO, Chile)

R. Cid FernandesR. Cid Fernandes (UFSC, Brazil) (UFSC, Brazil)Daniel KunthDaniel Kunth (IAP, France) (IAP, France)

Elena Terlevich Elena Terlevich (INAOE, Mexico)(INAOE, Mexico)Roberto TerlevichRoberto Terlevich (INAOE, Mexico) (INAOE, Mexico)

Paper I: Joguet B., Kunth D., Melnick J., et al. 2001, APaper I: Joguet B., Kunth D., Melnick J., et al. 2001, A&A, &A, 380, 19380, 19Paper II: Cid Fernandes R., Gu Q., Melnick J., et al. 200Paper II: Cid Fernandes R., Gu Q., Melnick J., et al. 2004, 4, MNRAS, 355, 273.MNRAS, 355, 273.

Starburst-AGN Starburst-AGN connectionconnection

Tight relation between black Tight relation between black hole and bulge mass hole and bulge mass

Sy2s: ideal objects for studying Sy2s: ideal objects for studying starburst-AGN connectionstarburst-AGN connection

~50% Sy2s are detected with ~50% Sy2s are detected with nuclear starburstnuclear starburst

NGC 4303

(1”=78pc)

NGC 3351

(1”=42pc)

DSS (5’)

UV (WFPC2,20”)

Starburst in Seyfert 2 GalaxiStarburst in Seyfert 2 Galaxi

eses

F210m

AGN!

F606W+0.4-8keV

F606w

0.4-8keV

Example: NGC 5135Example: NGC 5135

NGC 4303: STIS UV SPECTROSCOPY

STIS F25QTZ (0.025”/pixel)

Wavelength (Å)

NGC 4303 PA 220 ultraviolet

Luis Colina et al. (2002)

Luis Colina et al. (2002)

Luis Colina et al. (2002)

Ground-Ground-based based

spectrum spectrum includes includes

everythingeverything!!!!

Removing Stellar ContributionRemoving Stellar Contribution

Cid Fernandes, Gu, Melnick, et al. 2004, MNRAS

An Example:

Stellar population synthesis for ESO103-G35

Measuring Accurate FluxesMeasuring Accurate Fluxes

[OII]3727

[OIII]5007

Hβ

HγHδ

Results: Results: for a sample of Seyfert 2sfor a sample of Seyfert 2s

11 、 、 the relation between stellar anthe relation between stellar and gaseous extinction;d gaseous extinction;

22 、、 Luminosity vs. velocity dispersiLuminosity vs. velocity dispersion;on;

33 、、 the contribution from the starbthe contribution from the starburst to ionizing photons;urst to ionizing photons;

44 、、 the scatter of Faber-Jackson relthe scatter of Faber-Jackson relation for Seyfert 2 galaxiesation for Seyfert 2 galaxies

Results: Results: Ionizing Photons by StarburstIonizing Photons by Starburst

Results: Results: Faber-Jackson RelationFaber-Jackson Relation

Results: Results: Faber-Jackson RelationFaber-Jackson Relation

Scatter of F-J RelationScatter of F-J Relation

Scatter of F-J RelationScatter of F-J Relation

ConclusionsConclusions

22 、、 Photoionization by young stars can providPhotoionization by young stars can provide a substantial fraction of ionizing photons for e a substantial fraction of ionizing photons for Seyfert 2 nuclei. Seyfert 2 nuclei.

33 、 、 We confirm the existence of Faber-JacksoWe confirm the existence of Faber-Jackson relation for Seyfert 2 galaxies, and find the scn relation for Seyfert 2 galaxies, and find the scatter is correlated with the AGN activity.atter is correlated with the AGN activity.

11 、、 We measured the accurate fluxes of emissiWe measured the accurate fluxes of emission lines for a sample of 66 Seyfert 2 galaxies fron lines for a sample of 66 Seyfert 2 galaxies from the “pure” emission-line spectra.om the “pure” emission-line spectra.

Thanks !Thanks !

谢谢 谢谢 !!