An update on SMBHs in UCDs Steffen Mieske

ESO Chile

MODEST 17 meeting Prague

Sept. 18-22, 2017

Seth Voggel Chilingarian Afanasyev

Neumayer Baumgardt Lützgendorf

Hilker Frank

Hilker

UCD

Normal dwarf UCDs

Misgeld & Hilker 2011

UCD UCDs are believed to be

Massive star clusters (e.g. Fellhauer & Kroupa 2002,2005, Mieske+ 2002)

and/or Tidally threshed galaxies

(Bekki et al. 2003, Drinkwater et al. 2003, Pfeffer & Baumgardt 2013)

UCD

Normal dwarf

Michael Hilker

Measure global velocity dispersion

Dynamical modelling

using HST surface brightness

profiles

Include slit effects

Seeing limited spectroscopic observation

Elevated dynamical M/L of UCDs

UCDs

GCs

No dark mass

Dark mass

Literature: McLaughlin et al. 2005, Hasegan et al. 2005, Evstigneeva et al. 2007, Hilker et al. 2007, Mieske et al. 2008 & 2013, Chilingarian & Mamon 2008, Taylor et al. 2010, Chilingarian et al. 2011

Mieske et al. 2013

Dark mass

No dark mass

Normal dwarf UCDs

Misgeld & Hilker 2011

Mieske et al. (2013): calculate central BH masses in UCDs needed to elevate M/L (Mieske, Frank, Baumgardt, Luetzgendorf, Neumayer, Hilker, A&A 2013, 558, 14)

Typical inferred BH mass fraction is 10% of UCD mass

UCDs

Prediction: Massive UCDs should have ~10% relative BH masses

Luetzgendorf+ 2013

McConnell & Ma 2013

Mieske+ 2013

UCDs

Prediction: Massive UCDs should have ~10% relative BH masses

Massive BHs in UCDs would thus be relics of massive UCD progenitors. (Bekki et al. 2003, Pfeffer & Baumgardt 2013)

Mieske+ 2013

UCDs

Luetzgendorf+ 2013

McConnell & Ma 2013

To resolve the kinematical signature of an SMBH in UCDs,

one needs AO assisted spectroscopy

Joint Gemini North & VLT campaign to resolve UCD dynamics [PIs Seth, Mieske]

M60 UCD1

1”/80 pc!

M60!

NGC 4647!

M60-UCD1!

M60 UCD

Velocity Dispersion

Data

Model

Resolving the BH sphere of influence in M60-UCD1 (Seth et al. Nature 2014)

M60 UCD

Best fit Schwarzschild model

M_BH = 2.1 * 107 M*

Case of no BH rejected at 4σà A supermassive black hole

with 15% of the UCD mass

Resolving the BH sphere of influence in M60-UCD1 (Seth et al. Nature 2014)

•  Jeans models consistent with Schwarzschild models and isotropy

M60 UCD black hole in context

M60 UCD

Offset from the L-BH relation suggests significant tidal stripping Progenitor Bulge of ~1010 M*

What is the occupation fraction of SMBHs in UCDs?

Gemini+VLT campaign 2015+2016 (PIs Seth, Mieske) Goal: constrain central BH masses in 11 nearby UCDs (<20 Mpc) à Do SMBHs in UCDs contribute

significantly to the local SMBH density?

à Which fraction of UCDs originates from galaxies?

What is the occupation fraction of SMBHs in UCDs?

Gemini+VLT campaign 2015+2016 (PIs Seth, Mieske) Goal: constrain central BH masses in 11 nearby UCDs (<20 Mpc) à Do SMBHs in UCDs contribute

significantly to the local SMBH density?

à Which fraction of UCDs originates from galaxies?

New UCD BH results, 1 SINFONI+LGS of CenA UCDs

Voggel et al. (2017, in prep): No strong kinematical indication for SMBH in CenA UCDs

CenA UCD 330 (HST archival) CenA UCD 320 (ACS, courtesy A. Romanowsky)

New UCD BH results, 2

Ahn et al. (2017): SMBHs confirmed in two Virgo UCDs

Gemini-N NIFS

MBH= 4.4+-0.9 * 106M*

MBH= 5.8 +-0.9 * 106M*

New UCD BH results, 3 SINFONI+LGS of Fornax UCD 3

New UCD BH results, 3 SINFONI+LGS of Fornax UCD 3

PRELIMINARY radial velocity dispersion profile: - New SINFONI data, PSF is combination of 0.15” core and 1.0” wing - Seeing limited FLAMES data from Frank et al. (2011), PSF ~0.55”

Afanasyev et al. 2017, in preparation

New UCD BH results, 3 SINFONI +LGS of Fornax UCD 3

PRELIMINARY radial velocity dispersion profile: - New SINFONI data, PSF is combination of 0.15” core and 1.0” wing - Seeing limited FLAMES data from Frank et al. (2011), PSF ~0.55”

Mass of SMBH = 4 +2-1.5 *106 M*

(~5% of UCD mass)

Afanasyev et al. 2017, in preparation: SMBH detected at 98% confidence

What is the occupation fraction of SMBHs in UCDs: Update Q3/2017

SMBH occupation fraction: 4 out of 6 100% for UCD mass ~10^8 0% for UCD mass ~10^7

What is the occupation fraction of SMBHs in UCDs: Update Q3/2017

SMBH occupation fraction: 4 out of 6 100% for UCD mass ~10^8 0% for UCD mass ~10^7

Pfeffer et al. (2016) Number of stripped nuclei expected from simulations vs. number of observed CSSs

Summary 1.  UCDs (compact stellar systems more massive than ωCen) are a

mixed bag of objects consisting of massive star clusters and tidally stripped dwarf galaxies. 2.  Elevated dynamical M/L ratios of massive UCDs suggest dark mass

3.  SMBH occupation fraction of UCDs supports a scenario where:

•  UCDs with masses >107.5 M* mostly are tidally stripped galaxies

•  UCDs with masses <107 M* mostly are massive star clusters This is consistent with theoretical studies on the number ratio between tidally threshed naked nuclei and star clusters as f(m)

Outlook

•  Complete ongoing SMBH survey in UCDs •  And start going after UCD progenitors

•  Investigate alternative explanations for

elevated dynamical M/L of UCDs •  e.g. global IMF variation or central dark

remnants •  bad measurements....

•  Stellar population and kinematical trends

among large samples of GCs & UCDs

Outlook

?

Pechetti et al. (2017, almost accepted): Constraining SMBH masses in low mass ETGs (UCD progenitors)

based on ATLAS 3D

Announcement of opportunity at the VLT: MUSE-AO in narrow field mode to come soon

7“x7“ IFU in the optical with high perfomance AO (0.03“- 0.05“ resolution) Science verification planned for mid 2018

Announcement of opportunity at the VLT: MUSE-AO in narrow field mode to come soon

7“x7“ IFU in the optical with high perfomance AO (0.03“- 0.05“ resolution) Science verification planned for mid 2018

Announcement of opportunity at ESO: ESO fellowships Garching & Chile Deadline October 15

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