Observational constraints to boxy/peanut bulge formation time - - PowerPoint PPT Presentation

Observational constraints to boxy/peanut bulge formation time

Isabel Pérez

Departamento Física Teórica y del Cosmos, Universidad de Granada

• I. Martinez-Valpuesta(IAC), T. Ruiz-Lara(IAC), A. de Lorenzo-Caceres(IAC)), J. Falcón-

Barroso (IAC), Estrella Florido (UGR),R.M. Gonzalez-Delgado (IAA), M. Lyubenova (RUG), R.A. Marino (ETH), S.F. Sanchez (UAM), P. Sánchez-Bláquez (U. autóma de Madrid), G. van de Ven (MPI), A. Zurita (UGR)

Observations trace a boxy/peanut structure in the MW

V a l e n t i , e t a l . ( 2 1 6 )

based on RC stars from VVV

Boxy/peanut are ubiquitous

Martinez-Valpuesta et al. 2006

Boxy/peanut shape bulges in more than 40% of disc galaxies (Lutticke et al . 2000). Simulations show that boxy peanut bulges are bars (Combes & Sanders 1981; Athanassoula et

• al. 2002, Debattista et al. 2006,

etc) Observational evidence from spectroscopy of edge-on galaxies (e.g. Kuijken & Merrifield 1995; Bureau & Freeman 1999; Chung & Bureau 2004)

How do B/P bulges look like in less inclined galaxies?

Boxy/peanut shape bulges related to bar/lense structures seen face-on (Debattista et al. 2013, Laurikainen et al. 2017, 2014, Athanassoula et al 2015)

When and how bars and boxy/peanut bulges form?

• resolved star formation histories (near-field cosmology)

CALIFA survey PMAS (Ppak configuration) 3400-7300 Å Final spectral resolution FWHM ~ 6 Å and spatial resolutiion 1”

Subsample of 20 barred spirals beloging to size outliers such as NGC6032

When and how bars and boxy/peanut bulges form?

• star formation histories:

Integrated spectra from elliptical annuli bins

Stellar content analysis different approaches:

• Colours
• Line indices
• Full spectral fitting

Sanchez-Blazquez et al. 2011

``STEllar Content and Kinematics

via Maximum A Posteriori likelihood''STECKMAP (Ocvirk 2006)

Stellar Population models: MILES (Vazdekis et al. 2010: http://miles.iac.es)

Comparison between CMD and integrated stellar populations: LMC

Ruiz-Lara, Pérez, Gallart et al. 2015

Comparison between CMD and integrated stellar populations: LMC

WFPC2, reaching the oldest MS turn-off Aparicio & Gallart 2004 EFOSC2 Ruiz-Lara et al. 2015

Comparison between CMD and integrated stellar populations: LMC

Good agreement between state-of- the-art resolved stellar analysis and full spectral fitting (Ruiz-Lara, Pérez et al 2015)

When and how bars and boxy/peanut bulges form from star formation histories

Integrated spectra from elliptical annuli bins

S n a p s h

• t
• f

b a r a n d b u l g e f

• r

m a t i

• n

f r

• m

t h e S F H

• f

N G C 6 3 2

Pérez, Martinez-Valpuesta et al. 2017. Pérez, Martinez-Valpuesta et al. 2017.

S n a p s h

• t
• f

b a r a n d b u l g e f

• r

m a t i

• n

f r

• m

t h e S F H

• f

N G C 6 3 2

Pérez, Martinez-Valpuesta et al. 2017. Pérez, Martinez-Valpuesta et al. 2017.

Q u e n c h i n g

• f

t h e S F i n t h e ' i n n e r ' b a r : b a r a s a c

• n

v e y

• r

b e l t

Pérez, Martinez-Valpuesta et al. 2017.

B a r g r

• w

s f r

• m

d i s c m a t e r i a l

Pérez, Martinez-Valpuesta et al. 2017. Pérez, Martinez-Valpuesta et al. 2017.

S n a p s h

• t
• f

b a r a n d b u l g e f

• r

m a t i

• n

f r

• m

n u m e r i c a l s i m u l a t i

• n

s : b a r f

• r

m a t i

• n

a n d b u c k l i n g p e r i

• d

Pérez, Martinez-Valpuesta et al. 2017.

Summary

• The close relation between morphological features and SFHs

suggest a long-lasting bar

• The enhancement of star formation in the inner bar suggests,

based on the new simulation a relation with the bar formation and main growth, right before the buckling event. In this way we can estimate the buckling occurring around 8 Gyrs ago. We can also infer the formation of the stable disc and the bar at least before 10 Gyrs.

• After the event of the B/P formation, the bar grows again mainly

from disc material

• When the bar forms there is a quenching in the star formation of

the inner bar, suggesting that the bar can act as a conveyor belt, transferring material to the centre from the disc without forming stars within it.

• Sanchez-Menguiano, Sanchez, Perez et al 2017 accepted (T
• day!)
• 102 spiral galaxies with MUSE (part of the AMUSING project) 2D distributions Gas

abundances, stellar properties, kinematics, physical properties of HII regions