Embed Size (px)
Citation preview
The MUSE view on the dynamics of GCs
Sebastian Kamann (IAG)T.-O. Husser, B. Giesers, S. Dreizler (IAG),D. Krajnović, M. M. Roth, P. Weilbacher, M. Wendt, L. Wisotzki (Potsdam), E. Emsellem (ESO), J. Brinchmann (Leiden), R. Bacon (Lyon)
22016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Why integral-field spectroscopy?
“traditional” spectroscopyneeds isolated starsfew targets in centre of GConly brightest giants
centre of M13 (seeing ~0.7”)
32016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Why integral-field spectroscopy?
“traditional” spectroscopyneeds isolated starsfew targets in centre of GConly brightest giants
integral-field spectroscopyspatial information preservedanalysis similar to imagesdeblend sources
centre of M13 (seeing ~0.7”)
42016/04/21MODEST 2016 - Sebastian Kamann (IAG)
PampelMuse
PSF-based extraction for integral-field data (Kamann+13)example for NGC 6397:
52016/04/21MODEST 2016 - Sebastian Kamann (IAG)
An example: Looking for an IMBH in M92
seeing-limited IFU observations with PMAS~80 stellar spectra extracted
central dispersion from individual velocities: MBH < 10³ Msun
HST PMAS
Kamann+14
62016/04/21MODEST 2016 - Sebastian Kamann (IAG)
An example: Looking for an IMBH in M92
uncovering the integrated lightresolved stars along red giant branchknow positions & PSF
HST PMAS
72016/04/21MODEST 2016 - Sebastian Kamann (IAG)
An example: Looking for an IMBH in M92
uncovering the integrated lightresolved stars along red giant branchknow positions & PSF → subtract them
HST PMAS
82016/04/21MODEST 2016 - Sebastian Kamann (IAG)
An example: Looking for an IMBH in M92
uncovering the integrated lightresolved stars along red giant branchknow positions & PSF → subtract them
use resolved & unresolved stars : MBH < 7x10² Msun
HST PMAS
92016/04/21MODEST 2016 - Sebastian Kamann (IAG)
MUSE in a nutshell
commissioned 2014 at the VLT
panoramic IFScombination of 24 IFUs1'x1' FoV with 0.2” samplingλ ~ 4800Å – 9300Å
R ~ 1770 – 3590
“point and shoot”very stablehigh throughputexcellent optical quality
102016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Why MUSE?
>2 nights of PMAS: <5 hours of MUSE:
112016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Why MUSE?
>2 nights of PMAS: <5 hours of MUSE:
122016/04/21MODEST 2016 - Sebastian Kamann (IAG)
A large MUSE survey
ongoing observations of ~25 clusters with MUSE
aim: ~10000 stars per cluster, multi-epoch observations
science cases:binary fractions and periodsintermediate-mass black holesstellar parameter analysesserendipitous discoveries
currently: ~1000 exposures 30 TB of data
NGC 6441
132016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Legacy value of blind spectroscopy
example: Planetary nebula in NGC 6441
142016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Legacy value of blind spectroscopy
example: Planetary nebula in NGC 6441
152016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Our testbed: NGC 6397
nearby GCmoderate masscentral dispersion ~5 km/s[Fe/H] = -2
162016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Our testbed: NGC 6397
nearby GCmoderate masscentral dispersion ~5 km/s[Fe/H] = -2
19000 spectra / 12000 stars(could be even more ...)10500 spectra with S/N>10(almost) complete CMD
And
erso
n et
al.
(200
8)
192016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Velocity dispersion profile of NGC 6397
remember: σ~5 km/s challenging for kinematics!
at large radi:good agreement between MUSE and HR studies
at small radii:MUSE can probe much closer to the centre
202016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Velocity dispersion profile of NGC 6397
remember: σ~5 km/s challenging for kinematics!
at large radi:good agreement between MUSE and HR studies
at small radii:MUSE can probe much closer to the centre
kinematics as function of stellar mass
212016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Possibility for 2D kinematics
Rotation Dispersion
222016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Jeans models for NGC 6397
IMBH central excess of remnants
isotropic models using JAM code (Cappellari+08)central dispersion underestimated with constant M/Lexcess mass of 600 Msun
two explanations:
242016/04/21MODEST 2016 - Sebastian Kamann (IAG)
The other clusters
analysis of full sample currently in progresssome impressions:
NGC 3201
252016/04/21MODEST 2016 - Sebastian Kamann (IAG)
The other clusters
analysis of full sample currently in progresssome impressions:
NGC 3201NGC 7089
262016/04/21MODEST 2016 - Sebastian Kamann (IAG)
The other clusters
analysis of full sample currently in progresssome impressions:
NGC 3201NGC 7089NGC 2808
272016/04/21MODEST 2016 - Sebastian Kamann (IAG)
The other clusters
analysis of full sample currently in progresssome impressions:
NGC 3201NGC 7089NGC 2808
282016/03/22Massive multiplex MUSE spectroscopy in globular clusters S. Kamann (IAG)
Searching for binaries with MUSE
dedicated multi-epoch strategysearch for RV Variables
complementary to photometryBSSs, neutron stars, ...
example: NGC 3201~3200 stars with S/N > 105 epochs of data
analysis: Benjamin Giesers
292016/03/22Massive multiplex MUSE spectroscopy in globular clusters S. Kamann (IAG)
The binary fraction in NGC 3201
very consistent results from all epochs:
ultimate goal is to get binary periodsstill more epochs needed
(9.1 ± 1.4) %
302016/03/22Massive multiplex MUSE spectroscopy in globular clusters S. Kamann (IAG)
The binary fraction in NGC 3201
very consistent results from all epochs:
ultimate goal is to get binary periodsstill more epochs needed
(9.1 ± 1.4) %
Δt [days]
v_ra
d [k
m/ s
]
312016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Blind spectroscopy: BSSs in M30
Ferraro et al. (2010) MUSE RV variability
322016/04/21MODEST 2016 - Sebastian Kamann (IAG)
Conclusions
Crowded field 3D spectroscopy is a powerful tool to investigate globular cluster dynamics.
MUSE is great!spectroscopy with unprecedented sample sizes blind spectroscopy → wide unexplored spaceMUSE+AO is coming soon
