# Presentation: 228352

## RADIATIVELY INEFFICIENT ACCRETION DISKS IN LLAGNWHERE TO LOOK FOR THEM

- Marco Chiaberge
- Space Telescope Science Institute
- and INAF-IRA
- Alessandro Capetti      INAF – Torino Observatory
- Duccio Macchetto     STScI-ESA
- Roberto Gilli       INAF- Bologna Observatory
- Bill Sparks     - STScI

## THE HST VIEW OF LLAGN

**The nuclei of LLRG, Seyferts and LINERS**
**Where to look for RIAFs**

**2. NGC 4565 **
**   ****Are we finally detecting RIAF in the optical?**

## Accretion disks

**  ****“****standard”    Shakura-Sunyaev**** **
**    ****efficient radiative cooling   ********= L/Mc****2**** ~ 0.1**
**    ****geometrycally thin, optically thick disks**
**    ****L ~< L****E****  =  1.3 x 10****38  ****M/M****sun **** erg/s**

**.**

**Observed in QSO and  Seyfert galaxies**
**SED:  Blue bump – IR bump (hot dust)**

** ****RIAF**** (ADAF, CDAF, ADIOS, etc)**
**  ****m= Mc****2****/ L****E**** < m****crit**** ,    ******
**  ****L/ L****E**** << 1**
**  ****geometrically thick, optically thin**

**.**

**.**

**.**

**Where can we find them?  **
**SXT?, Galactic center?, LINERS?, LLRG?, Seyferts?**

**SED: synchrotron peak, IC peak(s), Bremsstrahlung**

## The Galactic center  - ADAF model (with winds)

**Quataert & Narayan 1999**

**The Galactic center  - ADAF model (with winds)**

## LLAGN

_**Radio quiet**_

_**Radio loud**_

- Nearby galaxies with some evidence for AGN activity
-                   Faint compact radio cores
-                   L(H) < 1040   erg s-1  (Ho et al. 1997)

**Low Ionization Nuclear Emission-line Regions**

**LINERs**

**Seyferts**

-  **Low Luminosity**
** ****Radio Galaxies (LLRG)**
**(FR I morphology)**

**[OIII] / [OII] < 1**

**[OIII] / [OII] > 1**

- (e.g. Heckman et al. 1980, Kewley et al. 2006)

## THE RADIO-OPTICAL  CORE CORRELATION 

**  ****Chiab, Capetti & Celotti 1999, Capetti et al. 2002, Verdoes-Kleijn et al. 2001**** **

**NON-THERMAL SYNCHROTRON EMISSION FROM THE BASE OF THE JET**

**THE RADIO-OPTICAL  CORE CORRELATION **
**                 ****OF FR I NUCLEI **

**Slope = 0.9 ******** ****0.1        ********r - o ****= 0.6 - 0.9  **

**For M****BH **** ~  10****8**** M******** ****the nuclei set the **
**upper limit to the disk luminosity **
**L****disk**** < 10****-5**** L****edd**

## LLAGN in the local universe

_**FR I**_**   ****radio galaxies from the 3CR catalog**

_**LINERs **_**   ****  d < 19 Mpc from the Palomar**
**                        ****sample of nearby galaxies**
**                            ****21/25 have HST images**

_**SEYFERT 1**_**   ****data from Ho & Peng 2001**
**                   ****   ****Palomar sample (d****med ****= 20 Mpc)**
**                            ****CfA sample (d****med ****= 80 Mpc)**
**                            ****25/32 have HST images**

**THE LOCAL AGNs ARE WELL REPRESENTED **
**BY  THESE 3  SAMPLES**

## Low luminosity radio galaxies (FRI) are unobscured

**                                                      ****(D. Macchetto’s   talk)**
**They do not host radiatively efficient accretion disks**
**                                      ****BUT**
**   ****Synchrotron radiation from the jet dominates **
**                         ****(at all wavelengths!!)**

**WHAT ABOUT THE OTHER CLASSES OF LLAGN**
**               ****IN THE LOCAL UNIVERSE?**** **

## Compact radio cores in LINERs and Seyferts

**       **
**                     **
**                      ****Unresolved on the mas scale**
**                                         ****T****B**** > 10****8 ****K**
**                               **
**                                ****Flat radio spectrum ********~ 0.0 - 0.6    ****(F************-********)**
**                       **
**                      ****The radio cores are variable**** **

**Radio cores are  synchrotron  **
**emission from a jet**
**        ****(Nagar et al 2002, Falcke et al. 1999,**
**                                       ****Anderson et al. 2004)**** **

**SIMILAR TO THE CORES OF RADIO GALAXIES**

## LLAGN - Seyfert 1 nuclei

**NGC 5033 - HST WFPC2 - V band**

## LLAGN - LINER nuclei

- _LLAGN - LINER nuclei_

**NGC 4278 - HST WFPC2- I band**

**NGC 4589 - HST WFPC2- I band**

- 15’’

- 15’’

- Unresolved nuclei in 40% of the objects

## LLAGN IN THE RADIO-OPTICAL PLANE

**FR I**

**Sy1**

**Radio loud**

**Radio quiet**

**Chiab et al 2005**

**LINERs**

## Elliptical galaxies with “core” profiles and  compact radio emission

- Balmaverde & Capetti 2006

**Elliptical galaxies with “core” profiles and  compact radio emission**

## BLACK HOLE MASS VS. RADIO LOUDNESS

**BLACK HOLE MASS VS. RADIO LOUDNESS**

**RQ**

**RL**

**Radio-loud AGN **
**in the SDSS**
**have M****BH****> 10****8 ****M****sun**
**(Mc Lure and Jarvis 2004)**

**FR I**

**SY 1**

**LINER**

## RL

**ACCRETION EFFICIENCY VS. RADIO LOUDNESS**

**RL**

**RQ**

**FR I**

**SY 1**

**LINERs**

**RIAF?**

**L****Edd**** = 1.3 x 10****38**** (M****BH****/M********) erg s****-1**

**SY1 NUCLEI**
**ARE NOT RL**

**The nuclear **
**radio loudness **
**traces the **
**emission process**

- o

## NGC 4565    (Chiab, Gilli, Macchetto & Sparks 2006)

**Low luminosity  Seyfert  d= 9.7 Mpc**
**Included in the Ho et al. 1997 sample (Palomar)**
**Moderate absorption in the X-rays   N****H**** = 2.5 x 10****21**** cm****-2**
**Only NARROW emission lines (Seyfert 2)**
**Compact 5GHz radio emission (VLBI)**
**Flat ********=0.15 radio spectrum**
**   **

## NGC 4565 AS SEEN WITH

**IR  1.6 ********m  NICMOS**

**OPTICAL (4500 A)  WFPC2**

**U-BAND 3300 A**
**ACS/HRC**

**NGC 4565 AS SEEN WITH**
**THE HUBBLE SPACE TELESCOPE**

## 1. What is the origin for  absorption?

**N****H**** = 2.5 x 10****21**** cm****-2                                  ****A****V ****= 1.2**

**NGC 4565 is a spiral galaxy seen almost edge-on       ********~ 10****o**
**In the Galaxy  at  b ~ 10****o      ****A****V  ****=  1.0-2.0**

**No need for nuclear obscuration**

**NGC 4565 is an unobscured Seyfert 2**
**           ****(e.g. Laor 2003, Elitzur & Sholsman  2006)**

## NGC4565 in the radio-optical plane

**NGC4565 in the radio-optical plane**

**Optical excess**
**w.r.t. synchrotron**
**emission**
**Optical radiation**
**from the accretion**
**process?**

## RL

**NGC 4565          BH mass = 2.8 x 10****7  ****M****sun**

**         ****Low L /L****edd**
**low radiative efficiency**
**              ****and/or**
**     ****low accretion rate**

**RL**

**RQ**

##  SED OF NGC 4565 COMPARED TO 

**    ****OTHER SEYFERT GALAXIES**

**The SED is unusual**
**No IR thermal excess**
**No blue bump**

## NGC4565 IN THE “FUNDAMENTAL PLANE 

**NGC4565 IN THE “FUNDAMENTAL PLANE **
**OF BLACK HOLE ACTIVITY”  **
**(Merloni et al  2003, Falcke et al. 2004)**

**QSOs**

**LLAGN**

**XRBs**

**Correlations are  **
**to be used with care!!**
**(Chiaberge, in prep)**

## CONCLUSIONS

**2. WE SHOULD SEARCH FOR RIAFs AMONG LLAGN **
**WITH ****RADIO QUIET NUCLEI****  (SEYFERT AND LINERS)**
**        ****IN HOW MANY OBJECTS CAN WE DETECT THEM?**

**3. IN NGC 4565  WE ARE MOST LIKELY**
**OBSERVING (FOR THE FIST TIME?)**
**AN ADAF-LIKE (RIAF) ACCRETION PROCESS**
**IN THE OPTICAL**

**4. NGC4565 IS AN “UNOBSCURED” SY2**
**     ****unobscured Sy2 do exist**

**FRI RADIO GALAXIES’ NUCLEI ARE JET DOMINATED **
**IF THEY HOST A RIAF, WE CAN’T DETECT IT **