Stellar halos & LSB features from deep VST surveys
Enrichetta Iodice et al. INAF- Capodimonte Astronomical Observatory Naples, Italy
NGC 5018 group VST color composite image of NGC1316 2°x1° field from ESO press release A long term project: VST survey of Early-type GAlaxieS (VEGAS) deep, multi-band (u g r i) imaging survey of early-type galaxies in groups & clusters @ VST
VEGAS is based on INAF GTO - 2011-16, PI: M. Capaccioli, ~55 nights - 2016-21, PI: E. Iodice, ~62 nights
VST is a 2.6m wide-field optical survey telescope, located @ ESO Cerro Paranal Observatory, Chile Field of view: 1°x1° Omega-Cam: 16k x 16k pixels
http://www.na.astro.it/vegas/VEGAS/Welcome.html Abel Cluster 1689 HST composite image From VEGAS to FDS
The Fornax Deep Survey with VST (FDS)
‣ joint project based on
VEGAS (P.I. E.Iodice) INAF GTO & FOCUS (P.I. R.Peletier) OmegaCam GTO
‣ new, multi-imaging (u, g, r, i bands) survey of the Fornax cluster
‣ FDS aims at covering 26 deg2 about the core of the Fornax cluster out to the virial radius, including the region of Fornax A VEGAS & FDS science aims
. map the light distribution and colors out to 8-10 Re and down to the 2 faint surface brightness levels of μg ≃ 31; μr ≃ 28; μi ≃ 27 mag/arcsec
. study the galaxy structures and theit faint stellar haloes, including the diffuse light component, inner substructures as signatures of recent accretion events, inner disks and bars
. detect the external low-surface brightness structures in galaxies, such as tidal tails, stellar streams and shells and study the connection with environment
. for galaxies at D < 40 Mpc, census the GCs and galaxy satellites in the outermost regions of the host galaxy and analyze their photometric properties
The full VEGAS sample will provide essential statistical constraints on theoretical models and enable discriminating among competing galaxy formation theories. VEGAS + FDS team INAF D. Forbes, Swinburne Univ., AU G. Busarello, Naples S. Mieske, ESO Paranal, CL M. Arnaboldi, ESO Garching, D M. Cantiello, Teramo E. Emsellem, ESO Garching, D G. D’Ago, Naples G. van de Ven, ESO Garching, D A. Grado, Naples M. Hilker, ESO Garching, D L. Greggio, Padua D. Krajnovic, AIP, D E. Iodice, Naples T. Lisker, Heidelberg Univ., D L. Limatola, Naples A. Cooper, Durham Univ., UK P. Merluzzi, Naples M. Capaccioli, Naples Univ. Fed. II, I D. De Cicco, Naples Univ. Fed. II, I N. Napolitano, Naples M. Paolillo, Naples Univ. Fed. II, I R. Rampazzo, Padua R. Peletier, Kapteyn Inst.. NL M. Ray, Naples C. Tortota, Kapteyn Inst., NL P. Schipani, Naples J. Falcon-Barroso, IAC, ES M. Spavone, Naples R. D’Abrusco, Smithsonian A.O., USA A. Romanovsky, S. Josè Univ., USA E. Bannikova, Kharkiv A. Zeleznyak, Kharkiv VEGAS + FDS publications
Iodice E. et al., 2018, A&A, submitted: The Fornax Deep Survey with VST. IV. Surface photometry of the bright ETGs insidee the virial radius Spavone M. et al., 2018, ApJ, accepted: VEGAS: A VST Early-type GAlaxy Survey III. Mapping the galaxy structure, interactions and intragroup light in the NGC5018 group Cantiello M. et al., 2018, A&A, 611, 93: VEGAS-SSS II. Comparing the globular cluster systems in NGC3115 and NGC1399 using VEGAS and FDS survey data
Iodice E. et al., 2017, ApJ, 851, 75: Intracluster Patches of Baryons in the Core of the Fornax Cluster Venhola A. et al., 2017, A&A, 608,142: The Fornax Deep Survey with VST. III. Low Surface Brightness (LSB) dwarfs and Ultra Diffuse Galaxies (UDGs) in the centre of the Fornax cluster Iodice E. et al., 2017, ApJ, 839, 21: The Fornax Deep Survey with VST. II. FornaxA: A Two-phase Assembly Caught in Act Spavone M. et al., 2017, A&A, 603, 38: VEGAS: A VST Early-type GAlaxy Survey II. Photometric study of giant ellipticals and their stellar halos
D’Abrusco R. et al., 2016, ApJL, 819, 31: The Extended Spatial Distribution of Globular Clusters in the Core of the Fornax Cluster Iodice E. et al., 2016, ApJ, 820, 42: The Fornax Deep Survey with VST. I. The Extended and Diffuse Stellar Halo of NGC 1399 out to 192 kpc
Cantiello M. et al., 2015, A&A, 576, 14: VEGAS-SSS. A VST early-type galaxy survey: analysis of small stellar systems. Testing the methodology on the globular cluster system in NGC 3115 Capaccioli M. et al. 2015, A&A, 581, 10: VEGAS: A VST Early-type GAlaxy Survey. I. Presentation and test case on the field of NGC 4472 Iodice E. et al. 2015, A&A, 574, 111: A forming wide polar-ring galaxy at z ∼ 0.05 in the VST Deep Field of the Fornax cluster Agenda of this talk
• Provocative images from VEGAS
• Results on stellar haloes & LSB features
• What did we learn? Observations vs theoretical predictions VEGAS ongoing projects: Mapping the galaxy structure, interactions, and intra-group light in the NGC5018 group
NGC 5018 group 2°x1° field from ESO press release (Spavone et al., ApJ, 2018) NGC 5018 group
MCG-03-34-013
NGC 5018 NGC 5022 VST color composite ugr VEGAS ongoing projects: NGC 5018 Mapping the galaxy structure, interactions, and intra-group light in the NGC5018 group
Spavone et al. 2018, ApJ, accepted NGC 5018 group
10 LIGL = 7.0610 L⊙ ∼ 41 % Lgroup
(g - r) = 0.8 mag ~ similar to the color to the halo of the BCG
VST color composite u g r VEGAS ongoing projects: NGC 5018 Mapping the galaxy structure, interactions, and intra-group light in the NGC5018 group
Spavone et al. 2018, ApJ, accepted Deep light profiles NGC 5018 group in u, g, r
~200 kpc
VST color composite ugr VEGAS ongoing projects: NGC 5018 Mapping the galaxy structure, interactions, and intra-group light in the NGC5018 group
Spavone et al. 2018, ApJ, accepted NGCNGC50185018 group Unsharp g-band masking MCG-03-34-013
NGC 5018 NGC 5022 VST color composite ugr VEGAS ongoing projects: NGC 5018 Mapping the galaxy structure, interactions, and intra-group light in the NGC5018 group
Spavone et al. 2018, ApJ, accepted NGC(g –5018r) color group map
MCG-03-34-013 (g - r) ~ 0.65-0.7 ± 0.02 mag
NGC 5018 NGC 5022 VST color composite ugr
VEGAS ongoing(g - r) ~ projects0.9-1.1 ± 0.5 mag: NGC 5018 Mapping the galaxy structure, interactions, and intra-group light in the NGC5018 group
Spavone et al. 2018, ApJ, accepted NGC1533 (Dorado) group
VST gr color composite
VEGAS ongoing projects: NGC 1533 Dorado group of galaxies
Master thesis of Arianna Cattapan, University of Padova, Italy NGC1533 very faint structures NGC1533 group
VST color composite gr VEGAS ongoing projects Dorado group of galaxies
g band - Master thesis of Arianna Cattapan, University of Padova, Italy structure of the bright galaxies (mB < 15 mag) inside R < Rvir
stellar halos in ETGs
LSB & dwarf galaxies
science on background objects GCs distribution FDS
Fornax Deep Survey (FDS) with VST Results & ongoing works
P.I.: E. Iodice & R. Peletier Tot int. time/field: u: 3 hrs u, g, r and i: completed in g & r: 2.3 hrs 2013+2014 and reduced i: 1.8 hrs g and i completed in 2014 and reduced
u and r completed in 2015 and reduced
g, r and i completed in Nov 2016, to be reduced
u completed in 2017
g and r completed in Nov 2015 g and r completed in Nov 2016, and reduced reduced u and i completed Oct 2017 i completed in Nov 2017 Fornax Deep Survey with VST
observation were completed in Nov 2017 - reduced data will be released in April 2019 Why Fornax?
RA 03h 38m - nearby, dense environment DEC -35d 30m - perfectly located for VST
20 Mpc - the mass assembly is still ongoing distance (FerrareseFornax etcore al. 2000) 13 NGC13997x10 M⊙ Mdyn (Drinkwater et al. 2001)
5x1041 erg/s LX (Jones et al. 1997)
370 km/s σ (Drinkwater et al. 2001)
0.7 Mpc Rvir (Drinkwater et al. 2001)
Fornax SW group NGC1316 Drinkwater et al. 2001 Why Fornax? multi-wavelength observations available/upcoming
Herschel survey R≤16 deg2 (P.I. Davies): cold dust in ~30 ETGs & LTGs ALMA survey on the Herschel sample (P.I. Davis) SAMI integral field spectroscopy of ~100 dwarf galaxies (P.I. Scott)
MUSE survey of the Fornax members inside Rvir (P.I. Sarzi/Iodice) MUSE survey of dwarfs (P.I. Peletier) VIMOS Survey of GCs (P.I. Napolitano) MeerKAT HI survey of Fornax (P.I. Serra) VISTA data (P.I. Puzia)
Archival data: Chandra, HST, GALEX FDS: galaxy structure, stellar halo & ICL
Iodice et al. 2016, ApJ 820, 42: The Fornax Deep Survey with VST. I. The extended and diffuse stellar halo of NGC1399 out to 192 kpc
Iodice et al. 2017, ApJ, 839, 21: The Fornax Deep Survey with VST. II. Fornax A: a two- phase assembly caught in act
Iodice et al. 2017, ApJ, 851, 75: Intracluster Patches of Baryons in the Core of the Fornax Cluster
Iodice et al. 2018, in preparation: The Fornax Deep Survey with VST. IV. Surface photometry of the bright early-type galaxies inside the virial radius
Ray et al. 2018, in preparation: The Fornax Deep Survey with VST. VI. Surface photometry of the bright late-type galaxies inside the virial radius
Spavone et al. 2018, in preparation: The Fornax Deep Survey with VST. VII. Stellar Halos of the bright early-type galaxies inside the virial radius FDS: the ETGs inside Rvir
within R < Rvir (~0.7 Mpc) FCC ETGs + LTGs members m < 15 mag B there are ~20 ETGs & ~10 LTGs VST mosaic of the Fornax cluster 2
R < Rvir (~3x3 deg )
degs 3 3 NGC1380 VST color composite image https://www.eso.org/public/news/eso1612/ FCC143 NGC1374 NGC1380B
NGC1375 NGC1381 FCC182
NGC1399 NGC1379
NGC1404 NGC1387
NGC1427A
NGC1389
NGC1386 NGC1365
N
E Rbreak 2 Re ≤ R ≤ 6 Re exponential decreasing component which contributes ~60% of NGC1399 192 kpc the total luminosity
μg ~ 31 mag/arcsec2
The extended stellar halo of NGC1399
Iodice et al. 2016, ApJ, 820, 42 NGC1399
NGC1387
The average colors in the streams are consistent with those in the outer envelope on the West side of NGC1387 The intracluster regions: it’s consistent with the formation the stellar bridge between byNGC1399 the stripping from & NGC1387NGC1387 halo Iodice et al. 2016, ApJ, 820, 42 ProjectedProjected distribution distribution of GCsof blue (red+blue GCs vs) lightvs light
D’Abrusco et al. 2016 NGC1380
NGC1374 NGC1380B
NGC1381 FCC182 ICL NGC1399 NGC1379
NGC1404 NGC1387
NGC1389
N - 10 < R < 40 arcmin (~ 58-230 kpc) 2 - μr ~ 29 - 30 mag/arcsec E 9 - Lg ~ 8.3x10 L⊙ The intracluster regions: the- (gICL-r) ~ 0.7 mag
Iodice et al. 2017, ApJ, 851, 75 N ICL vs IC GCs
E
blue GCs from D’Abrusco et al. 2016 blue GCs from Cantiello et al. 2017 NGC1380
FCC143 NGC1374 NGC1380B NGC1375Surface photometry: NGC1381 FCC182
NGC1399 ✤ deep images & isophotal analysis NGC1379 ✤ total magnitudes & Re in ugri NGC1404 NGC1387 ✤ g-r & g-i integrated colors, color profiles & 2D color maps NGC1389 ✤ stellar M/L ✤ overview of the galaxy structure (including stellar halos) vs environment
N
E
The bright ETGs in the Rvir of the cluster
Iodice et al. 2018, A&A, submitted NGC1380
FCC143 NGC1374 NGC1380B NGC1375 NGC1381 unprecedented limitsFCC182 reached in mapping NGC1399 the light and color distributionNGC1379 s
NGC1404 NGC1387 ~ 10 − 15Re 2 2 μr≥ 27 mag/arcsec (μB ≥NGC1389 28 mag/arcsec )
N
E What is the new contribution from the FDS?
Iodice et al. 2018, A&A, submitted theThe bulkbright of the ETGsgravitationalin the interactionsRvir of the betweencluster galaxiesFCC143: RESULTS should have happened on the W-NW side of the cluster, where most of the bright ETGs are located and where the intra-cluster baryons are found
FCC161 FCC147
asymmetric stellar halos
FCC184 The bright ETGs in the Rvir of the cluster: RESULTS stellar halos made by the accretion outskirts > 10 -30 kpc of rather massive, metal-rich satellite galaxies
blue colors in the outskirts only allow for contribution< 1 of- 3minor kpc mergers ∑~ 45 gal/Mpc
D ~ 0.3 Mpc FDS: the SW group (NGC 1316) Fornax core FCC ETGs + LTGs members mB < 15 mag NGC1399
Fornax SW group NGC1316 Drinkwater et al. 2001 NGC1316 NGC 1316 - VST color composite image https://www.eso.org/public/images/eso1734a/ (3x2 degs)
NGC1326A
NGC1326B
NGC1326
NGC1316C NGC1317 NGC1341 NGC1310
FCC028 NGC1316 VST color composite image https://www.eso.org/public/images/eso1734a/ (3x2 degs)
NGC1326A
NGC1326B
NGC1326
NGC1316C NGC1317 NGC1341 NGC1310
FCC028 NGC1316 VST g band surfaceSchmidt photometry plate by Malin out to 33 arcmin (~200 kpc ~15Re)
FCC143 NGC1374
NGC1375
10 arcmin
Fornax A: a two-phase assembly caught in act
Iodice et al. 2017, ApJ, 839, 21 FCC143 NGC1374 same color
NGC1375 as halo data analysis (light and color distribution) suggests that we are catching in act the second phase of the mass assembly in this galaxy: accretion of smaller satellites is going on
bluer
Fornax A: a two-phase assembly caught in act
Iodice et al. 2017, ApJ, 839, 21
NGC1399 vs NGC1316: two giants in comparison
- NGC1399 is an more evolved phase with respect to NGC1316 - both galaxies have an r1/4 spheroid - stellar envelope is still forming in NGC1316 but already settled with an exponential decline Cooper et al. 2010 stellar halo in NGC1316 formed by Observations vs theoreticalgradual accretion predictions of several progenitors:
similar morphology + total extension the build up of the stellar halo in NGC1316
stellar
• SB (r band) = 26.6 - 30.6 mag/arcsec2 halo 7 - 9 • exponential profile similar to the total luminosity (10 10 L⊙) • luminous substructures = recent events & colors 0.54 ≲ g-r ≲0.6 mg 9 L(L2+L3) = 7x10 L⊙ of the dwarf galaxies inside the envelope g-r =0.54 mag Observations vs theoretical predictions Fit of the SB profiles to identify the main components dominating the galaxy light
1/n I/I0 = exp[-k(r/re) ]
n = 1 exponential n = 4 de Vaucouelurs
Spavone et al. 2017, A&A, 603, 38 Observations vs theoretical predictions Spavone et al. 2017, A&A, 603, 38 ETGs in high-density Pillepich et al. 2018 regions of Fornax R>100 kpc
Pillepich et al. 2018 TOT
tot R<30 kpc center+ICL
massive* stellar halos M
in denseM* enviroment?
situ/
-
ex
*
accreted/
M total ETGs in low-density
regionsM* of Fornax
M*TOT [M☉] Concluding remarks
The large mosaic obtained with the 1 deg2 FoV of OmegaCam@VST + the arcsec-level angular resolution of 0.21 arcsec/pixel + the large integration time
the galaxy structure from the brightest inner regions to the faint outskirts, out to the intracluster regions stellar halos properties (structure, colors, mass fraction) as function of the environment provides observables to be compared with simulations