Welcome!


Illustration of a dark star in the early universe. (Photo Credit: The University of Utah)

The cluster of excellence "Connecting Particles with the Cosmos" combines unique expertise on accelerator and detector physics, particle physics, astro- and astroparticle-physics with cosmology, string theory and mathematical physics in Hamburg. It aims at providing significant contributions to the worldwide research programme in particle physics, strengthening its connections to cosmology and exploring its implications on the fundamental laws of nature.

The young investigator group on "Cosmic radiation fields and search for dark matter in the early universe" investigates signatures of dark matter in diffuse radiation background fields produced in the early Universe. The group will also explore the complementarity of indirect searches with searches at colliders for new physics. Our research is done in close cooperation with astrophysics facilities, especially the Hamburg Observatory and the Astroparticle Physics Group at the University of Hamburg.


From Nov 9-12, 2010 we organized the workshop Cosmic Radiation Fields - Sources in the early Universe discussing the extragalactic infrared background resulting from sources in the early universe with a focus on the effect of dark matter on the early star formation.


News

2012

CTA WORKSHOP ON EBL AND COSMOLOGY
6.11.2012

We are organizing a workshop on "The CTA EBL and cosmology physics case" at the Max Planck Institute for Physics in Munich from November 28th to 30th.


LEXI Meeting 2012 next week
2.10.2012

The annual LEXI cluster Meeting will take place on October 11/12 at DESY, Hamburg. The meeting will feature several talks focusing on the perspectives of various research activities within the Cluster, as well as many talks reporting on the status of current research projects. The variety of topics covered will make the meeting interesting for the whole Cluster as audience, and shall serve as a basis for discussions about the future of the LEXI research projects. Andreas Maurer and Manuel Meyer from our group will there to present their work.


ARTICLE ON STAR FORMATION RATE VS EBL PUBLISHED
2.10.2012

Our article on "Probing the peak of the star formation rate density with the extragalactic background light" just got published in the Monthly Notices of the Royal Astronomical Society. In the article recent contraints on the density of the extragalactic background light (EBL) are combined with a detailed phenomenological modeling of the emission of stars and dust in galaxies to derive contraints on the star formation rate density (SFRD). The article is available online at MNRAS or astro-ph.

LEXI CRF YIG @ Gamma 2012
4.7.2012

Next week the LEXI young investigator group on cosmic radiation fields will be at the 5th International Symposium on High-Energy Gamma-Ray Astronomy (Gamma2012) in Heidelberg. Catch up with us on Monday night during the Poster Session where Pepa presents posters on "Population study of Blazars detected at Very High Energy gamma-ray" and an "Unprecedented gamma-ray flare from PG 1553+113 in Spring 2012", Andi on "Very High Energy gamma ray absorption via localized diffuse radiation fields", Manuel on "Indications for a low opacity Universe from Fermi data" and "Limits on the extragalactic background light in the Fermi era", and Martin on "PyFACT: Python and FITS Analysis for Cherenkov Telescopes". Don't miss Martin talks on Thursday afternoon 15:20 on "How recent limits on the extragalactic background light constrain the star formation history". See you all there!

EBL LIMIT PAPER PUBLISHED IN A&A
6.6.2012

Our paper on new constraints on the extragalactic background light using data from the Fermi satellite and ground based very high energy gamma-ray instruments has recently been published in Astronomy & Astrophysics.

LEXI GROUP @ WISPY DAY
27.2.2012

Manuel Meyer and Martin Raue gave lectures at the WISPy lecture day at DESY Hamburg. The workshop, jointly organized by DESY and the University of Hamburg, focused on theoretical studies as well as experiments (most notably ALPS and SHIPS) searching for Weakly Interacting Slim Particles dubbed WISPs. The theoretical foundations of WISPs, their role in extensions of the Standard Model of particle physics and a (possible) WISP- related exemplary phenomenon were discussed on the lecture day.

The lectures have been broadcasted via the DESY webcast and the recordings of Manuel's and Martin's lecture can viewed below.

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An exemplary phenomenon: the TeV-photon transparency of the universe - The environment: extragalactic background light (Martin Raue, Hamburg Uni.)

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An exemplary phenomenon: the TeV-photon transparency of the universe - The observations: active galactic nuclei (Manuel Meyer, Hamburg Uni.)

NEW CONSTRAINS ON THE EBL FROM HE/VHE OBSERVATIONS
15.2.2012

Our paper on new limits on the density of the extragalactic background light from ground and space based gamma-ray observatories has been accepted for publication in Astronomy and Astrophysics. You can pick up a copy on the arXiv. In the paper a larger sample of VHE spectra as measured by H.E.S.S., MAGIC, and VERITAS, in combination with data from the Fermi-LAT instrument is used to derive strong constrains on the EBL density over a wide wavelength range from the ultraviolet to the far-infrared. Only minimal assumption on the intrinsic spectrum are used and novel methods utilizing the integrated VHE emission are presented. The EBL is found to be constrained close to the lower limits derived from integrated galaxy counts, which represent the strongest limits on the EBL density over such a wide wavelength range today!

DARKS STARS ON SPACE.COM
7.2.2012

space.com ran an article on our recent paper on dark matter powered stars and the extragalactic background light (see previous news item).

NEW PAPER ON DARKS STARS AND THE EBL
9.1.2012

Our paper on the contribution of dark matter powered stars to the extragalctic background light got recently accepted for publication in the Astrophysical Journal. In the paper, the contribution of dark matter powered stars to the diffuse metagalactic photon fields in the optical to infrared wavelength regime are calculate for a variety of different scenarios. Limit on the density of these photon field are then used to derive contrains on the properties of the Dark Stars.

2011

CTA CONSORTIUM MEETING - MADRID, SPAIN
28.11. - 2.12.2011

Last week Martin Raue went to Madrid to take part in the CTA Consortium Meeting. The Cherenkov Telescope Array (CTA) is an initiative to build the next generation ground-based very high energy gamma-ray instrument. It will serve as an open observatory to a wide astrophysics community and will provide a deep insight into the non-thermal high-energy universe.


DESY OPEN HOUSE 2011
29.10.2011

The LEXI YIG actively participated in the DESY open house exhibition, helping to build Fermi satellite paper models, presenting and discussing their research with the general public, and hosting a live video feed to our collegues at the H.E.S.S. site in Namibia.


A CHANGE IN MANAGEMENT
1.10.2011

We had a change in management in our group: Tanja Kneiske moved to a position at the Frauenhofer Institut für Windenergie und Energiesystemtechnik. We wish her all the best at her new institute. Martin Raue will take over the group leader position of the LEXI YIG.

HEPRO 3 CONFERENCE - BARCELONA, SPAIN
26.7. - 1.7.2011

Martin Raue will be at the workshop "High Energy Phenomena in Relativistic Outflows III", talking about the detection of a VHE gamma-ray flare from the radio galaxy M 87 in 2010 and associated multi-wavelength observations.

CRF 2010 PROCEEDINGS PUBLISHED
3.5.2011

The proceedings of our workshop Cosmic Radiation Fields - Sources in the early Universe have been published in the Proceedings of Science.

AGN WORKSHOP - MUONIO, FINLAND
11. - 15.4.2011

Tanja Kneiske and Martin Raue will be at the workshop "Beamed and Un-Beamed Gamma-Rays from Galaxies" in Muonio, Finland speaking about the extragalactic background light and dark matter powered stars in the early universe.


2010

6. - 10.12.2010
Andreas Maurer will be at the "25th Texas Symposium on Relativistic Astrophysics" speaking on "Constraints on dark matter powered stars from the extragalactic background light". Martin Raue will be there as well, co-presenting a poster on "The potential of the next generation Cherenkov telescopes to constrain the EBL" and several poster on the detection of new gamma-ray emitting active galactic nuclei with the H.E.S.S. instrument.

9. - 12.11.2010
Last week we had our workshop on "Cosmic radiation fields - sources in the early universe". The transparencies can be found on the webpage and there will be proceeding in the Proceedings of Science. Thank you all for coming and see you next time.

8. - 10.9.2010
Martin Raue will speak at the "Scineghe - Gamma-ray Astrophysics in the Multimessenger context" workshop on "EBL studies with ground based instruments - status and potential of future instruments".

26. - 30.7.2010
Andreas Maurer will be at the "IDM 2010 - 8th international workshop on Identification of Dark Matter" conference in Montpellier speaking on "Watching dark matter stars burn - possible signatures of Dark Stars in the EBL".

18. - 25.7.2010
Tanja Kneiske and Martin Raue will be at the cospar 10 conference in Bremen.

5. - 9.7.2010
Tanja Kneiske will be at the The 6th Patras Workshop on Axions, WIMPs and WISPs in Zurich.

8. - 12.3.2010
Next week M. Raue will be at the "First Stars and Galaxies: Challenges in the Next Decade" conference in Austin, Texas, discussing the future research on the early universe and the first stars.

25./26.2.2010
A. Maurer presented a poster on dark stars and the extragalactic background light at the "Astroteilchenphysik in Deutschland, Status und Perspektiven 2010" meeting in Zeuthen, Germany.