Archivi tag: galaxy formation

The Formation and Evolution of Exponential Disks in Galaxies

Exponential stellar disks are ubiquitous. The stars in both spiral and dwarf galaxies are generally found to be organized in exponential disks, even to very low surface densities and in both stellar dominated and gas dominated galactic environments. But why is this? The associated gas disks do not fall off with radius in the same manner. Furthermore, star formation is highly lumpy. How does lumpy star formation produce distributions of stars that fall off smoothly. And how are these profiles maintained over many Gyr? Continua a leggere The Formation and Evolution of Exponential Disks in Galaxies

Satellite galaxies and dwarfs in the Local Group

The local neighborhood surrounding the Milky Way and M31 is teeming with small satellite galaxies whose properties are of immense interest. In the past few years the number of dwarfs observed in the local group has nearly doubled, mostly due to increased sensitivity in observations. These observations have posed a number of challenges to the theoretical modeling of dwarf galaxies. Continua a leggere Satellite galaxies and dwarfs in the Local Group

Dwarf Galaxies as Cosmological Probes

Recent wide-field surveys have revolutionized our understanding of the Local Group of Galaxies. The Sloan Digital Sky Survey, in particular, has more than doubled the number of known dwarf galaxies orbiting the Milky Way and revealed a new population of ultrafaint dwarf satellites. At the same time, advances in computational cosmology have led to improved predictions for the properties of the smallest dark matter halos that host dwarf galaxies in the current paradigm of structure formation, the Lambda Cold Dark Matter model.
Continua a leggere Dwarf Galaxies as Cosmological Probes

From dark matter to galaxies

Recent years have witnessed the establishment of the concordance cosmology. Under the Cold Dark Matter scenario,  cosmic structures are characteristic of dark matter haloes embedded in the cosmic web. Galaxies are thought to form at the center of dark matter haloes via gas cooling and fragmentation. Various models and numerical simulations have been developed to model the formation and evolution of galaxies. Observations of the galaxy population and local group are used to constrain the cold dark matter model on large and small scales. 
Continua a leggere From dark matter to galaxies

The Formation and Growth of Galaxies in the Young Universe

It is now ~4 years since the last galaxy-evolution ski conference at Obergurgl. In the December 2009 meeting, highlights included the first results from Herschel, and very early data from WFC3 on the refurbished Hubble Space Telescope. In the intervening years several major surveys have been completed by Hubble and Herschel, wide-field near-infrared imaging has begun to be delivered by VISTA, SCUBA2 has commenced sub-mm surveys on the JCMT, near-infrared multi-object spectrographs have commenced operation on 8-m class telescopes, and the first results have emerged from ALMA and Planck. By April 2014 ALMA Cycle 1 will be nearing completion, KMOS will have been commissioned on the VLT, Hyper Suprime-Cam will be operational on Subaru, and the next generation of radio surveys will be underway.

The aim of this meeting will to review and discuss these observational advances, alongside progress in theory/simulation, with a dual focus on galaxy/black-hole evolution at z > 2, and reionization/first-galaxies at z > 6.

The Impact of Feedback on Star and Galaxy Formation

After several decades of theoretical developments and spectacular observations of star formation sites and star forming galaxies, our understanding of star formation in the universe has profoundly evolved. Designing a theory for star formation based on physical first principles is now within our grasp, but to reach this goal we must grapple with the central  role feedback processes from young stars play in regulating star formation in galaxies and in determining the properties of newly born stellar populations deep inside molecular clouds. Modeling feedback processes such as radiation from young stars, stellar winds and ultimately explosive events like supernovae is very challenging. The relative importance of different forms of feedback energy (thermal energy, ionizing and continuum radiation, cosmic rays,  kinetic energy in jets) is still under debate, and the energy injection often occurs at very small scales that are poorly resolved by computer simulations or telescope imaging. Moreover, this energy also couples to very large scales, driving turbulence within the ISM and powering the ejection of powerful galactic winds, both of which contribute to regulating the global star formation efficiency into disk galaxies.

The goal of this conference, the kick-off meeting for our program on the physics of star formation feedback, is to set the scene for the three following months in Santa Barbara.  Focus areas will include discussion of the detailed nature and efficacy of various stellar feedback mechanisms, new theoretical and observational developments on how feedback regulates star formation at a range of scales, and inter-comparisons of numerical methods for implementing feedback in molecular clouds and in galaxies. During the week, various sessions will be dedicated to discuss critical areas where new developments  and new collaborations are needed. For example, observations of large scale gas motions within the Galaxy will be used to set constraints on theoretical and numerical models of the galactic fountain,  while detailed post-processing of computer simulations could be used by observers to infer the physical  properties of stellar outflows. Interactions between theorists and observers, and between experts in small scale and  large scale phenomenon, will shed some light on the role of these feedback processes for regulating star formation.

Astronomy in the TMT Era

TMT-J invites you to join us for a two-day workshop “Astronomy in the TMT Era” in Tokyo, Japan to explore the potential of TMT in astronomy. TMT is an international project to build and operate a 30 meter telescope located on Mauna Kea. The program will consist of talks and discussions exploring TMT science with first-light and future instruments. We anticipate a broad range of topics on new results, new interpretation and theory, discussing with clear implication the best usage of TMT “in the TMT era”. The second half of Day 2 will focus on the 2nd generation instruments, which will further bring exciting TMT capabilities to meet diverse scientific needs. Each section will open with one or two invited reviews, followed by contributed talks. This workshop followed by the TMT SAC meeting on Oct. 18. is an opportunity to bring together the Japanese astronomical community to the TMT project and promote the development of international collaborations of science and instrumentation.

Topics:

  • – Cosmology
  • – Galaxy formation & evolution, AGN
  • – Nearby galaxies
  • – Stars, exoplanets & star formation
  • – Time domain & polarimetry sciences
  • – 2nd generation instrumentation

Alpine Cosmology Workshop 2013

This is an annual workshop organized since 2009 by scientists of University of HelsinkiMax-Planck Institute for extraterrestrial Physics (MPE) and The University of Innsbruck.

The concept of the workshop is to combine a scientific part, in which each participant delivers a review on their topic with a group activity in which every participant is engaged. To this end we have selected to conduct the workshop at several huts located in the Alps, connected by hiking trails. Each day has approximately 6 hours of the workshop and 6 hours of hiking, during which the participants usually continue the discussion of the scientific topics and establish new collaborations. The no escape principle, and no contact to outside, possible during the workshop, are unique attributes of the conference and allow participants to concentrate entirely on the subject of the conference, which includes:

  • Cosmology and surveys
  • Physics of galaxy clusters
  • Coevolution of galaxies and black holes

Galaxies within the Cosmic Web

The Kavli Institute for Cosmological Physics (KICP) at the University of Chicago will host “Galaxies within the Cosmic Web” workshop on June 17-21, 2013. The workshop will be held in the lecture hall 120 in the Kersten Physics Teaching Center (KPTC) on the University of Chicago campus. During the last thirty years, studies of structure formation have played a key role in establishing the Cold Dark Matter (CDM) paradigm of structure formation in an expanding universe. In the CDM model the initial Gaussian density perturbations are shaped by gravity into a cosmic web of voids and filaments, at the intersection of which galaxies and galaxy clusters are mainly thought to form. Although the model has been a tremendous success in explaining the observed large-scale structure of the universe, many key aspects of how galaxies form and evolve within this cosmic web of dark matter and diffuse gas are still not understood. The gaps in our understanding not only hamper interpretation of the wealth of observational data on galaxy evolution, but also represent a major systematic uncertainty for cosmological probes of the accelerated expansion of the universe, the nature of gravity, and forecasts and interpretation of direct and indirect dark matter searches. This workshop will assemble both observers and theorists (target size ~60-80 people) who work on all key aspects of galaxy formation to assess recent progress and, most importantly, to germinate new ideas for how to improve our understanding of galaxy formation, the relation between the baryonic mass of galaxies and their parent halos, the effects of galaxy assembly and associated feedback on the spatial distribution of dark matter, and the interpretation of galaxy clustering and bias from large surveys to constrain the evolution of dark energy. The focus of the meeting will be on the most rapidly developing and interesting topics of research, and the format will include ample time for discussion and unstructured interaction.

SKA Science Workshop in East-Asia 2013

The SKA (Square Kilometer Array) is a next-generation radio telescope consisting of 3000 antennas, planned by an international organization. The SKA has an unprecedentedly wide field, wide frequency coverage, high sensitivity, and high angular resolution simultaneously at 100 MHz-10GHz. It will allow us to probe the Universe at a level of sensitivity and completeness orders of magnitude beyond what has previously been achieved, targeting scientific themes from cosmology to extragalactic life. In 2012, a significant progress has been made for the SKA, including the final decision of the sites of the SKA. Also, the international SKA science working groups were reorganized, and the scientific activity of the SKA is just starting in a unified way. In East-Asia, we had an East Asia SKA Workshop 2011 and made a kick-off discussion to have efficient collaborations among East-Asian countries both in scientific and engineering sides. Now in 2013, we organize an SKA Science Workshop in East-Asia. The aim of this workshop is to put together the scientific efforts in various fields of astrophysics from East-Asia as well as other countries. Plenary review talks, oral and poster presentations are planned. We also take significant time for a deep scientific discussion for each field of astrophysics so that we can produce new scientific proposals. Given that the SKA will have been a major radio telescope in the next decade, we encourage young researchers including PhD students to come and join the workshop. This Workshop is supported by Leadership Development Program for Space Exploration and Research, and the Kobayashi Maskawa Institute for the origin of particles and the universe, Nagoya University.