Archivi tag: galaxy evolution

Tribes of the deep sky

The distribution of galaxies populating the largest scale structures in the Universe today are visible different than the population in lower density environments.  From massive brightest cluster galaxies existing in the cores of groups and clusters to the increasing number of dwarf galaxies with density, multi-wavelength studies of clusters shed light on how these different populations have formed and currently evolving.   In order to understand the evolution of galaxies in these high density environments, it is critical to construct a coherent picture of the different populations between today and the high redshift Universe.
This conference will focus on comparing multi-wavelength observations of populations in clusters and groups to state of the art theoretical predictions. Topics for the conference will include:
  • Brightest Cluster Galaxies
  • Quiescent Populations
  • Star forming galaxies
  • Active Galactic Nuclei
  • Dwarf galaxies
We hope to explore both the interplay between these different types as well as looking at how these populations evolve from clusters seen today to high redshift proto-clusters.

Transformational Science with the SKA, Synergies with ALMA and other Contemporary Instruments

In 2014 it will be over twenty years since the first discussions of the SKA and the ambitious call for a radio telescope with a considerable increase in sensitivity (two orders of magnitude) over existing instruments. It will also be ten years since the publication of the rationale for the SKA in ‘Science with the SKA’ (Carilli and Rawlings). These years have seen much progress in radio astronomy, especially in the development of instruments covering the full radio wavelength range from millimetres to metres (ALMA to LOFAR). In May 2012, the sites for the putative SKA were decided, with the bulk of the collecting area to be built in Africa.

This symposium will discuss progress in SKA science, as well as its relationship to scientific results from other contemporary instruments. Meeting sessions will encompass all aspects of contemporary radio astronomy, including the early Universe, HI in galaxies, star formation, galaxy evolution, pulsars and transients.

  • A clearer understanding of the SKA scientific goals and their role in contemporary astrophysics.
  • A broadening of our understanding of current themes in radio astronomy and the experimental and theoretical methodology used to tackle them.
  • A new experience in outreach, where our research students interact directly with high school learners.

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

Studying Galaxy Evolution: a Galaxy Zoo conference

How do galaxies form and evolve? What shapes galaxies? What are the roles of supermassive black holes and bars in galaxy evolution? Nature and nurture both play important roles in galaxy evolution and the aims of this meeting are to: (i) further develop our understanding of the many underlying physical processes that are responsible for shaping the galaxies that we observe in the Universe around us; and (ii) showcase the high impact scientific contributions by Galaxy Zoo to the study of galaxy evolution. To catch the galaxies in the act of transformation, huge samples of galaxies are needed before we can identify one that is in the stage of transformation, especially if these transformation processes occur relatively quickly. A direct consequence of very large surveys is the emergence of “big data” science which severely challenges traditional data processing techniques. Hence, there exists a great need to develop a variety of techniques to fully maximise the scientific return.

Whether you’re already working with Galaxy Zoo data, curious about how it might inform your science, or if you just want to spend a few days thinking about galaxy evolution, we hope you’ll join us. With more large surveys coming from next generation facilities such as LSST and ASKAP, this meeting will also act as a springboard for Galaxy Zoo-like projects using very large datasets.

Galaxy Evolution Over Five Decades

The last few years have seen a transformation in our understanding of the formation and evolution of galaxies. These advances have been driven by observations that cover a broad range in wavelength. In the years ahead, new facilities like the JWST, CCAT, the LMT, ALMA, the JVLA, LOFAR and the SKA will shed further light on how galaxies form by providing huge increases in sensitivity over five decades in wavelength: from the near-infrared to long radio-wavelengths. This conference will bring together researchers from around the world to discuss the current state of the field and future directions that should be taken as these new telescopes come into operation. The meeting is in honour of Professor Malcolm Longair, who has made invaluable contributions to our knowledge of galaxy evolution and to the Astrophysics Group at the Cavendish Laboratory.

Scientific areas to be covered:

  • AGN and Galaxy Evolution
  • Gas in Galaxies
  • The High-redshift Universe and the First Galaxies
  • Galaxy Assembly and Cosmic Star-formation History
  • Galaxy Clusters and the Role of Environment

SALT observes the power of quasars

Un gruppo di astrofisici di del Dartmouth College hanno studiato le modalità con cui i quasar, e i buchi neri che in essi risiedono, influenzano le galassie ospiti. I ricercatori hanno documentato l’immensa radiazione emessa dai quasar che si estende per migliaia di anni-luce nello spazio, fino ai bordi più esterni della galassia.

For the first time, we are able to see the actual extent to which these quasars and their black holes can affect their galaxies, and we see that it is limited only by the amount of gas in the galaxy” says Kevin Hainline. “The radiation excites gas all the way to the margins of the galaxy and stops only when it runs out of gas“. The illumination of gas can have a profound effect, since gas that is lit up and heated by the quasar is less able to collapse under its own gravity and form new stars. Thus, the tiny central black hole and its quasar can slow down star formation in the entire galaxy and influence how the galaxy grows and changes over time. “This is exciting because we know from a number of different independent arguments that these quasars have a profound effect on the galaxies in which they live“, Ryan Hickox says.

There is a lot of controversy about how they actually influence the galaxy, but now we have one aspect of the interaction that can extend on the scale of the entire galaxy. Nobody had seen this before“.

The radiation released by a quasar covers the entire electromagnetic spectrum, from radio waves and microwaves at the low-frequency end through infrared, ultraviolet, and X-rays, to high-frequency gamma rays. A central black hole, also called an active galactic nucleus, may grow by swallowing material from the surrounding interstellar gas, releasing energy in the process. This leads to the creation of a quasar, emitting radiation that illuminates the gas present throughout the galaxy. “If you take this powerful, bright radiation source in the center of the galaxy and blast the gas with its radiation, it will get excited in just the same way the neon gets excited in neon lamps, producing light“, says Hickox. “The gas will produce very specific frequencies of light that only a quasar can produce. This light functioned as a tracer that we were able to use to follow the gas excited by the black hole out to large distances“.

Quasars are small compared to a galaxy, like a grain of sand on a beach, but the power of their radiation can extend to the galactic boundaries and beyond.

Hickox, Hainline, and their co-authors based their conclusions on observations made with the Southern African Large Telescope (SALT), the largest optical telescope in the southern hemisphere. Dartmouth is a partner in SALT, giving faculty and students access to the instrument. The observations were performed using spectroscopy, where light is broken down into its component wavelengths. “For this particular kind of experiment, it is among the best telescopes in the world“, says Hickox. They also used data from NASA’s Wide-field Infrared Survey Explorer (WISE), a space telescope that imaged the whole sky in the infrared. The scientists used observations in infrared light because they give a particularly reliable measure of the total energy output by the quasar.

Dartmouth College: Shedding New Light on the Brightest Objects in the Universe

arXiv: SALT Long-slit Spectroscopy of Luminous Obscured Quasars: An Upper Limit on the Size of the Narrow-Line Region?

Sesto 2013: Tracing Cosmic Evolution with Clusters of Galaxies

Following the Sesto-2001 and Sesto-2007 Conferences, we are organizing a new conference in Sesto Pusteria, in the heart of the Italian Dolomites, dedicated to studies of the evolution and formation of cosmic structures with galaxy clusters, with the title “Sesto 2013 – Tracing Cosmic Evolution with Clusters of Galaxies“.

In recent years, X-ray and radio observations have revealed in ever increasing detail the complexity of the Intra-Cluster Medium, while still leaving unexplained the riddle of cool cores.  A growing number of optical/IR studies of clusters above z~1 and up to z~2 have shed new light on the formation history of cluster galaxies, revamping at the same time the role of galaxy clusters in constraining the nature of dark matter and dark energy.  Searches for and studies of clusters based on the SZ effect now flourish. The systematic use of gravitational lensing with spectacular HST data has enabled the dark matter mass distribution in the inner cores of cluster halos to be explored in detail. Recent numerical simulations, with an increasing level of realism and more sophisticated implementation of relevant physical processes, have led to better understanding of both the achievements and shortcomings of the current modeling of galaxy clusters in the cosmological framework. At a time when a new generation of large volume, multi-wavelength cosmological surveys is unfolding, and CMB observations from Planck are establishing the cosmological scenario of structure formation with unprecedented accuracy, this conference aims to bring together both theoretical and observational astronomers working at different wavelengths to discuss recent results and future prospects in the study of cosmic evolution through galaxy clusters.

The meeting will focus on three main topics:
  1. The matter distribution in clusters from different methods
  2. The cycle of baryons in clusters  and their galaxy populations
  3. Cosmology and large-scale structure of the Universe

Feeding, Feedback, and Fireworks

Late in June 2013, the Australian Astronomical Observatory (AAO) will be holding an international astronomy conference which will be hosted in the tropical paradise of Hamilton Island, Queensland, Australia. The meeting, entitled “Feeding, Feedback, and Fireworks: Celebrating Our Cosmic Landscape“, will be the 6th of the Southern Cross Conference Series, jointly supported by the AAO and CSIRO Astronomy and Space Science (CASS). The Southern Cross Astrophysics Conferences are held annually around Australia with the aim of attracting international experts with wide ranging skills to discuss a particular astrophysical topic. This conference will focus on galaxy evolution and how various feedback and feeding processes transfer energy into and out of galaxies. We intend to bring together observations, from radio to X-rays, and the best available theoretical models, to create a more complete picture of our cosmic landscape.

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.

The Modern Radio Universe 2013

80 years ago, in spring 1933, Karl Jansky published his discovery of cosmic radio emission. This paved the way not only for a new discipline, radio astronomy, but also for an exploration of the universe that now encompasses almost the entire electromagnetic window. Today, radio astronomy is about to enter into yet another new era with a number of new or upgraded radio facilities coming online and major new initiatives, like the Square Kilometre Array (SKA), are starting up. This conference will try to highlight the original and exciting science currently being produced by radio astronomical telescopes, such as the GBT, Effelsberg, LOFAR, ALMA, the JVLA, GMRT, eMERLIN, EVN, VLBA, as well as pathfinder experiments of the SKA, and others.
Science areas that will be discussed are among others: Cosmology, galaxy evolution, AGN and compact objects, star formation, interstellar medium, The Milky Way and Galactic science, radio transients, fundamental and astroparticle physics, extreme physics and associated theory. This fresh view on the radio universe will improve our current knowledge of the universe and highlight new trends in radio astronomy. The science delivered by the radio astronomical community addresses key questions in modern astrophysics that may lead us to even more ambitious science goals to be targeted by future radio facilities like the SKA.
The last Modern Radio Universe took place 2007 in Manchester commemorating 50 years of the Lovell telescope and looking forward towards the SKA. This issue of the conference commemorates the groundbreaking work of Karl Jansky 80 years ago and comes 40 years after the Effelsberg 100 metre telescope started operations. While combining past and future in this conference, the main focus of the science presentations, however, will be to make an inventory of outstanding science results that are presently being obtained with the new or upgraded facilities.