Starbursts in COSMOS: the Galaxies, the Knots, the Scenario

 Starbursts in COSMOS: the Galaxies, the Knots, the Scenario Casiana Muñoz-­‐Tuñón Ins0tuto de Astro6sica de Canarias •  Rodrigo Hinojosa Goñi (IAC) •  Jairo Méndez-­‐Abreu (ST Andrews-­‐ UK) Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 1 Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 2 COSMOS
Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 3 Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 4 Results •  Catalogue with 220 Starbursts (EW>80A) •  RedshiN up to 0.5 •  Search first in ZCOSMOS-­‐ extended to Phot-­‐
COSMOS •  Catalogue with the clumps in each galaxy. Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 5 Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 6 The Galaxies (I) Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 7 The Galaxies (II) Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 8 HST images Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 9 Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 10 The Knots (I) Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 11 The Knots (II) Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 12 The Knots (II) Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 13 The Scenario (I) •  Starburst galaxies in COSMOS have mean masses of log (M)=8 Msun. •  83/220 are Sknot// 79/220 are sknot+ difuse light// 32/220 are mknots •  The knots are “similar” (SSFR) •  The more massive are bigger and they are in the centre of the galaxy. Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 14 The Scenario (II) Hinojosa Goñi, Muñoz Tuñón & Méndez Abreu, A&A, 2015Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 15 Triggering?? Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 16 Angeles´s birthday April 2015-­‐ la cristalera-­‐ Figure 1 from Tadpole Galaxies in the Hubble Ultra Deep Field 17 Miraflores Bruce G. Elmegreen and Debra Meloy Elmegreen 2010 ApJ 722 1895. Elmegreen, D. etal., 2012, Ap.J., 750, 95. Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 18 Search using the SDSS •  Blue Compact Dwarf Galaxies (BCDs) (DR6) •  Systemahc Search for Quiescent BCDs (21.500 glxs) •  Automahc Classificahon of Sloan Spectra (DR7) •  Search for XMP targets. •  Complete census of the nearby BCDs, QBCDs and XMPs Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 19 BCDs and QBCDs in SSDS DR6 birthday April 2015-­‐ la cristalera-­‐ (SA, MT etal , 2008, ApJ., 685, Angeles´s 198-­‐210) Miraflores 20 Angeles´s birthday April 2015-­‐ la cristalera-­‐ 21 SA, MT et al., 2008, ApJ., 685; Amorín, MT, L. Aguerri, 2007, A&A, 467; 2009, A&A, 501. Miraflores Systematic Search for Extremely Metal-poor Galaxies in the Sloan Digital Sky
Survey (DR9). Morales-Luis et al. 2011 ApJ 743 77.
Spatial distribution of the XMPs
: 129 from the literature + 32 new targets from sloan
Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 22 The spectrum decides de shape !!! Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 23 -­‐ High spectral resoluhon 1D spectra around Hа (R~10000) -­‐ IDS@INT and ALFOSc@NOT -­‐ 7 tadpoles (50%) of the sample -­‐ spectrograph slit along then head-­‐tail direchon birthday April 2015-­‐ la cristalera-­‐ SA, MT et al., 2013, Ap.J., 7Angeles´s 67, 74. Miraflores 24 Brightness Profiles - lopsided light distribuhon (as expected) - Tadpole head defined to be at zero distance Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 25 Velocity Curves - 5(or 6) out of 7 rotate - Tadpole head oNen off-­‐centered with respect to the center of rotahon Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 26 Metallicity (Oxygen abundance)
-­‐ O/H based on [NII]6583/Hα - Metallicity gradients, lower at center and increasing outwards
- two of them XMP (extremely
metal poor) galaxy
Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 27 We propose the SF in XMP tadpole galaxies is triggered by cold flow accrehon. They are not triggered by galaxy mergers… see
Filho et al., ApJ, 802, 82, 2015,
See more in Sanchez Almeida, Elmegreen, Muñoz-Tuñón &
Elmegreen, 2014, A&ARv, 22, 71.
Accretion of external flows of pristine gas (cold-flows), which numerical
simulations predicts is thought to be the main mode of disks growth at
high z..
The incoming gas hit and heats the proto-disk, and is expected to form
giant clumps that spiral in and merge into a central spheroid (Noguchi
1999; Genzel et al. 2008; Elmegreen et al. 2008).
Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 28 Future work… with the catalogue of starburst
galaxies in COSMOS… test the cold flow accretion
as triggering mechanism that provides the gas to
feed the clumps
Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 29 No conclussion(s)…just more to do
Angeles´s birthday April 2015-­‐ la cristalera-­‐ Miraflores 30