13 January, 2015

Conferences 2015

Some handpicked conferences that may be interesting for extragalactic guys. Source CADC

01 October, 2014

New semester. new lectures

This semester (WS2014) I'm involved in two lectures

The first one aims to describe the latest advances in Galaxy Evolution, how the galaxies become "read and dead", what processes lead to this status and the links to the cosmic star formation history, galaxy mass-function, (in)efficiency of star-formation and the role of environment.  This lecture is done together with Christian Maier.

The second is a seminar together with Prof. Gerhard Hensler where we will review the latest publications of the evolution of galaxies in clusters.


10 July, 2014

Galaxies in 3D across the Universe: Day 4

Well, in the end I couldn't write much yesterday. Hopefully more come today.

Session 1

Phil Hopkins on the reasons of the inefficient star formation (2%). You may have heard about the problem. It shows up at different scales. The K-S relation is about how many stars you need to balance gravity, not how fast the gas collapses. He is doing detailed simulations including all relevant physics. Multiphase ISM develops "spontaneously". Feedback, inflows & outflows are important players. He is able to reproduce the M*-Mhalo relation WITHOUT fine tuning. He is also making fake IFU data. Physical processes affect the different gas phases differently.

09 July, 2014

Galaxies in 3D across the Universe: Day 3

I'm chairing the first session so I don't know whether I'll have time to liveblog. Anyway it is a great pleasure to have Jeff Kenney as a review speaker. I first heard about him as an undergraduate when we analyzed the Kinney-Calzetti atlas of galaxies for some lecture. Even partial stripping can make a galaxy red in less than 0.5Gyr! In Virgo. Even the galactic halo can remove the gas of dwarf satellite galaxies.

08 July, 2014

Galaxies in 3D across the Universe: Day 2

Well, being part of the LOC means losing a lot of things, scientific wise. Yesterday was mostly dedicated to make sure that everything worked fine. It mostly did! So I feel very very relieved and it is a wonderful to see that the hard work of months produce fruits. So, it is not much I can say of the talks of yesterday. As most of the things are now fixed, hopefully I will have more time to enjoy the science. So I liveblog

The talks will be soonish online: http://galaxy3d.univie.ac.at

Some folks have set up a twitter hashtag where you can follow the developments: Follow us at #iaus309

Session 1

The day started with a wonderful summary by Sebastian Sanchez on the IFUs surveys with of course a detailed overview to his baby project: CALIFA

Now Roberto Cid Fernandez describes the methods being applied to CALIFA datacubes: Starlight. Derivation of stellar population parameters via full fitting of the spectra. Describes uncertainties: Choice of SSP models is dominant in comparison to others, e.g. extinction.

Now it comes the results of the methods described before: Rosa Gonzalez Delgado speaks now about Stellar Mass Growth of galaxies. Results are also today at the top of the astro-ph listing: http://arxiv.org/abs/1407.1315

Polychronis Papaderos describes the origin of faint emission lines in the outskirts of early type galaxies. There is some low level star formation but ionization by pAGB stars may be dominant. Interesting speculation regarding low (optical) luminosity AGNs (LINERS, etc) which shine in X-rays (and radio):  Consider the Ly-alpha scape fraction

Now is the turn of Chung-Pei Ma and her MASSIVE survey looking to the most massive galaxies in the local Universe. Firs results appeared yesterday in astro-ph. Combines the lare FoV of the Mitchell IFU (107x107 arcsec2 ->~2Reff) with AO instruments observing the centers for BH masses. Complementary to ATLAS3D in the mass-size parameter space.

Session 2

Review talk by Stephane Courteau on galaxy masses. Describes degeneracies between baryon and DM distributions. DM content at all radii still uncertain: "We are swimming in a sea of uncertainty". Tully-Fisher relation: Galaxies of all surface brightness lie in the same relation. Why, why, why? It has deep roots. To explain the TF relation we need to allow for halo expansion. 70% of the mass in spiral galaxies is in DM at R~2.2Rd. There must be a variation of the IMF between elliptical and spirals (confirmed by lensing)

Spiral galaxies has a bimodal distribution on surface brightness! Two stables models? LSB DM dominates, HSB baryion dominates the center,

To measure mass of galaxies get M(r) and sigma(r) as deeply and homogenous as possible. Key quesion: Distribution of angular momentum for DM and baryons Cross-talk between components: Need Mstar/Mtot as function of R!! Excellent talk! Good question on extra baryonic components ;-) yeah, there is also IGM, IGL, etc.

James Allen now describes the  SAMI survey. About 1000 galaxies observed so far,  including those in clusters :-) Periodic public release with fully calibrated datacubes. First one later this month. Lisa Fogarty follows on a study of ETGs in three clusters using SAMI.Fraction of slow rotators hardly depends on environment, wrt fast rotators. @Lisa Sigma_3 is not a good statistic, too sensitive to close neighbors. Issues in the selection of slow/fast rotators when you are close to the origin. 

It is now the turn of Michaela Hirschmann with some theoretical input on the origin of the metallicity gradients. Feedback delays metal enrichment. Stellar winds seem necessary to reproduce metallicity gradients.

Session 3

Well, arrived slightly late, but still in time to catch Daniela Calzetti talk. Few take-away messages: No universal good tracer of SF, all have caveats and they should be used depending on the galaxy type. Also important to subtract the diffuse component. There is as much information in the scatter of the K-S law as is in the slope. "What's the best star formation tracer? Calzetti: Depends on where your measuring and on type of galaxy".

Loretta Dunne speaking on the dust content evolution in the Universe. Dust is good tracer of the gas as it is CO. Audience  question some assumptions, specially regarding dust temperature. Now is the turn of Denis Burgarella, focus on the WISH telescope and includes 1arcmin2 IFU, in space. It may detect 1 z=14 galaxy per square degree. Interesting. WISH and EUCLID are complementary, not competing. Somewhat different capabilities. Invites for collaborations.

Connection problems....

David Fisher in z~0.1 clumpy galaxies. Local counterparts of the high-z galaxies. Very high gas fractions! Many similar properties, be careful with the clump sizes. They are 'merge' when simulating the galaxy at z=2.

Mooses Mogotsi trying to connect galaxy kinematics with SF properties. Central velocity gradient seems to be connected to the surface SFR density. Interesting, Is kinematical shear important in SF properties?

Lodovico Cocatto on couterotating galaxies. Accurate modeling of the different components,  stellar population of counterotating components are clearly separated from main component and are younger.

HL Talks

Alessia Moretti: Superdense galaxies in clusters. Most of them are fast rotators. Michael Hilker: Nice analysis of the kinematical structures of the globular cluster system of the Hydra I cluster. Carlos Barbosa stress the importance of the ICL. Evelyn Johnson: A step further, spectroscopic bulge-disk decomposition. After quenching of spirals a final burst occurs at the center using highly enriched gas (Wow). Waiting for IFU data for further testing. Pavel Jachym talks about ESO137-001 a fantastic sample of ram pressure stripping. Interesting mixing of gas phases, basically you get all. I cannot think in many other examples except BCGs. Finds low SF formation efficiency in the stripped tails, not unlike of outer galaxy disks. Rory Smith in simulations of galaxy harassment. They have systematically lower velocities. Time to test this! Peter Erwin on bulge-to-disk decomposition, compare kinematics to photometry. S0 and Sa galaxies have both, bulges and pseudobulges. Looks at the anisotropy parameter. Remco van den Bosch on the HET Massive galaxy survey. Measuring direct BH masses in compact galaxies. Mischa Schirmer is reconstructing the life of AGNs over 100.000 years by looking at the light echos. The 'green beans' are very rare 1-in-1000 deg2. Christian Maier on the mass-metallicity relation at z~1.5. Junko Ueda now on the evolution of the merger remnants. Most will become ellipticals, but some can also become late type galaxies.

Now time for the dinner!


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