Neutrinos from active black holes, sources of ultra high energy cosmic rays

A correlation between the highest energy Cosmic Rays (above ~ EeV) and the distribution of active galactic nuclei (AGN) gives rise to a prediction of neutrino production in the same sources. In this paper, we present a detailed AGN model, predicting neutrino production near the foot of the jet, where the photon fields from the disk and synchrotron radiation from the jet itself create high optical depths for proton-photon interactions. The protons escape from later shocks where the emission region is optically thin for proton-photon interactions. Consequently, Cosmic Rays are predicted to come from FR-I galaxies, independent of the orientation of the source. Neutrinos, on the other hand, are only observable from sources directing their jet towards Earth, i.e. flat spectrum radio sources and in particular BL Lac type objects, due to the strongly boosted neutrino emission.Comment: Accepted for publication in Astroparticle Physics; 30 pages, 8 figure

The diffuse neutrino flux from FR-II radio galaxies and blazars: A source property based estimate

Water and ice Cherenkov telescopes of the present and future aim for the detection of a neutrino signal from extraterrestrial sources at energies E>PeV. Some of the most promising extragalactic sources are Active Galactic Nuclei (AGN). In this paper, the neutrino flux from two kinds of AGN sources will be estimated assuming photohadronic interactions in the jet of the AGN. The first analyzed sample contains FR-II radio galaxies while the second AGN type examined are blazars. The result is highly dependent on the proton's index of the energy spectrum. To normalize the spectrum, the connection between neutrino and disk luminosity will be used by applying the jet-disk symbiosis model from Falcke and Biermann (1995). The maximum proton energy and thus, also the maximum neutrino energy of the source is connected to its disk luminosity, which was shown by Lovelace (1976) and was confirmed by Falcke et al. (1995).Comment: 24 pages, 14 figures, to be published in Astroparticle Physic

Neutrinos from photo-hadronic interactions in Pks2155-304

The high-peaked BL Lac object Pks2155-304 shows high variability at multiwavelengths, i.e. from optical up to TeV energies. A giant flare of around 1 hour at X-ray and TeV energies was observed in 2006. In this context, it is essential to understand the physical processes in terms of the primary spectrum and the radiation emitted, since high-energy emission can arise in both leptonic and hadronic processes. In this contribution, we investigate the possibility of neutrino production in photo-hadronic interactions. In particular, we predict a direct correlation between optical and TeV energies at sufficiently high optical radiation fields. We show that in the blazar Pks2155-304, the optical emission in the low-state is sufficient to lead to photo-hadronic interactions and therefore to the production of high-energy photons.Comment: contribution to RICAP 2009 and ICRC 2009 - both papers are combined in one draft. 11 pages, 3 figure

On the detectability of primordial black holes in the Galaxy

In the mass range of 1e15 g up to 1e26 g, primordial black holes (PBHs) as a possible contribution to the dark matter are still unexplored. In this contribution, we investigate the possibility of an electromagnetic signal from PBH interactions with astrophysical objects in the Galaxy. We find that a signal from passages cannot be observed, since, depending on the mass, either the interaction probability or the energy loss is too small. Further, we discuss possible effects from high-mass PBHs at masses >1e26 g, where PBHs can still contribute to the dark matter at the order of ~10%. Here, we find that a significant fraction of PBHs can be captured in the Hubble time. These captures could therefore lead to detectable effects.Comment: 10 pages, 3 figures, paper to be presented at ICRC 200

Evaluation des Projektes "Student im Praktikum"

Im Wintersemester 1995/96 entstand das Projekt Student im Praktikum. PD Dr. Eibl- Eibesfeldt möchte den Studenten der ersten Semester die Möglichkeit geben, Erfahrung im klinischen Bereich zu sammeln. Dieses innovative Projekt lädt den jungen Mediziner ein, ihren Dozenten eine Woche im Klinikalltag zu begleiten. Da das Angebot so zahlreich und gerne angenommen wird, wird es nun jedes Semester an der LMU angeboten. Die ehemaligen Teilnehmer wurden zweimal über dieses Praktikum befragt. Die erste Umfrage ist ein schriftlicher persönlicher Bogen mit semantischen, differentialen und freien Fragen. Sie wurde direkt im Anschluss an das Praktikum durchgeführt und zeigt bei den Befragten eine durchwegs positive Reaktion auf dieses Angebot. Die Möglichkeit Kontakt mit echten Patienten zu bekommen, wird als willkommene Abwechslung zum theoretischen Studienalltag gesehen. Den einzigen Verbesserungsvorschlag sehen die Studenten darin, den Zeitraum des einwöchigen Praktikums zu erweitern. Die zweite Umfrage wurde im Rahmen der Dissertation entwickelt. Sie ist ein schriftlicher anonymer Bogen aus 25 geschlossenen Fragen und drei freien Fragen. Es wird der Ablauf des Praktikums, das Rollenverständnis des Arztberufes und den Aspekt des Lernens genau beleuchtet. Entscheidend für diese Umfrage ist die Tatsache, dass die Studenten das Praktikum aus der Retrospektive betrachten. Die ein bis zwei Jahre, die zwischen dem Praktikum und der Beantwortung des Fragebogens liegen, geben den Studenten die Möglichkeit weitere Erfahrung im Studium zu sammeln und somit das Praktikum in einem größeren Kontext zu sehen. Es ist bezeichnend, dass von den 50 versandten Bogen 34 innerhalb von drei Wochen beantwortet wurden und sich die Studenten auch noch nach einer längeren Zeitspanne an das Praktikum erinnern können. Diese außeruniversitäre Veranstaltung stieß durchwegs auf positive Reaktion. Einzig wie auch schon die erste Umfrage zeigt, wird die Dauer von nur einer Woche als zu kurz angesehen. Bei der Bewertung zum Rollenverständnis des Arztberufs zeichnen sich nicht so eindeutige Ergebnisse ab. Die jungen Studenten haben teilweise noch kein gefestigtes Bild von der Arbeit eines Arztes. Die genaue Vorstellung ihrer zukünftigen Arbeit wird erst im Laufe des Studiums und weiterer praktischer Erfahrung geprägt und oft auch wieder geändert. Einig sind sich die Befragten, dass sie viel über den sozialen Aspekt des Arztberufes und über die Arzt-Patient- Beziehung erfahren haben. Der letzte Teil der Umfrage beschäftigt sich mit dem Lernerfolg. Hier zeichnen sich auch eindeutige Ergebnisse ab. Der praktische Lernerfolg wird allgemein als hoch eingestuft, wohingegen beim theoretischen Nutzen die Antworten sehr breit gestreut sind und sich somit keine eindeutige Tendenz erkennen lässt. Auf den Punkt gebracht lässt sich sagen, dass das Praktikum positiv angenommen wird, der Initiator PD Dr. Eibl-Eibesfeldt gelobt wird und ein Einblick in den späteren Beruf erworben wird. In der vorliegenden Arbeit wurde sehr viel Kritik an dem großen theoretischen Anteil des Medizinstudiums geübt. Dem ist hinzuzufügen, dass die neue Approbationsordnung den Weg für eine praxisorientiertere Ausbildung bereitet hat. Der Zeitpunkt des Praktikums der befragten Studenten fällt aber noch in die alte Studienordnung. Deshalb wird in dieser Arbeit nur auf diese Zeit eingegangen, eine Betrachtung der neuen Studienordnung würde den Rahmen dieser Arbeit sprengen

Status of neutrino astronomy

Astrophysical neutrinos can be produced in proton interactions of charged cosmic rays with ambient photon or baryonic fields. Cosmic rays are observed in balloon, satellite and air shower experiments every day, from below 1e9 eV up to macroscopic energies of 1e21 eV. The observation of different photon fields has been done ever since, today with detections ranging from radio wavelengths up to very high-energy photons in the TeV range. The leading question for neutrino astronomers is now which sources provide a combination of efficient proton acceleration with sufficiently high photon fields or baryonic targets at the same time in order to produce a neutrino flux that is high enough to exceed the background of atmospheric neutrinos. There are only two confirmed astrophysical neutrino sources up to today: the sun and SuperNova 1987A emit and emitted neutrinos at MeV energies. The aim of large underground Cherenkov telescopes like IceCube and KM3NeT is the detection of neutrinos at energies above 100 GeV. In this paper, recent developments of neutrino flux modeling for the most promising extragalactic sources, gamma ray bursts and active galactic nuclei, are presented.Comment: Talk given at Neutrino 2008, Christchurch (New Zealand) 6 pages, 4 figures, 1 tabl

Status of neutrino astronomy

Astrophysical neutrinos can be produced in proton interactions of charged cosmic rays with ambient photon or baryonic fields. Cosmic rays are observed in balloon, satellite and air shower experiments every day, from below 1e9 eV up to macroscopic energies of 1e21 eV. The observation of different photon fields has been done ever since, today with detections ranging from radio wavelengths up to very high-energy photons in the TeV range. The leading question for neutrino astronomers is now which sources provide a combination of efficient proton acceleration with sufficiently high photon fields or baryonic targets at the same time in order to produce a neutrino flux that is high enough to exceed the background of atmospheric neutrinos. There are only two confirmed astrophysical neutrino sources up to today: the sun and SuperNova 1987A emit and emitted neutrinos at MeV energies. The aim of large underground Cherenkov telescopes like IceCube and KM3NeT is the detection of neutrinos at energies above 100 GeV. In this paper, recent developments of neutrino flux modeling for the most promising extragalactic sources, gamma ray bursts and active galactic nuclei, are presented.Comment: Talk given at Neutrino 2008, Christchurch (New Zealand) 6 pages, 4 figures, 1 tabl

Status of neutrino astronomy

Astrophysical neutrinos can be produced in proton interactions of charged cosmic rays with ambient photon or baryonic fields. Cosmic rays are observed in balloon, satellite and air shower experiments every day, from below 1e9 eV up to macroscopic energies of 1e21 eV. The observation of different photon fields has been done ever since, today with detections ranging from radio wavelengths up to very high-energy photons in the TeV range. The leading question for neutrino astronomers is now which sources provide a combination of efficient proton acceleration with sufficiently high photon fields or baryonic targets at the same time in order to produce a neutrino flux that is high enough to exceed the background of atmospheric neutrinos. There are only two confirmed astrophysical neutrino sources up to today: the sun and SuperNova 1987A emit and emitted neutrinos at MeV energies. The aim of large underground Cherenkov telescopes like IceCube and KM3NeT is the detection of neutrinos at energies above 100 GeV. In this paper, recent developments of neutrino flux modeling for the most promising extragalactic sources, gamma ray bursts and active galactic nuclei, are presented.Comment: Talk given at Neutrino 2008, Christchurch (New Zealand) 6 pages, 4 figures, 1 tabl

Cosmic Rays VI - Starburst galaxies at multiwavelengths

We propose an explanation for the far-infrared/radio correlation of galaxies in terms of the energy balance of the interstellar medium and determine the flux from high-energy photons and neutrinos from starburst galaxies. We present a catalog of the 127 brightest starburst galaxies with redshifts of z<0.03. In order to investigate the correlation between radio- and far-infrared emission, we apply the leaky box approximation. Further, we derive photon- and neutrino spectra from proton-proton interactions in supernova remnants (SNRs). Here, we assume that a fraction of the SNR's energy is transferred to the acceleration of cosmic rays. We also investigate the possibility of detecting Gamma Ray Bursts from nearby starburst galaxies, using the catalog defined here. We show that the radio emission is only weakly dependent on the magnetic field. It turns out that the intensity of the radio signal is directly proportional to the number of supernova explosions, which scales with the far-infrared luminosity. In addition, we find that high-energy photons from proton-proton interactions in SNRs in starbursts can make up several percent of the diffuse gamma-ray background. The neutrino flux from the same sources has a maximum energy of ~1e5 GeV. Neutrinos can, on the other hand, can be observed if a Gamma Ray Burst happens in a nearby starburst. About 0.03 GRBs per year are expected to occur in the entire catalog. The true number is expected to be even higher, since we only include the brightest sources. The number of events per burst in IceCube varies between about one event and more than 1000 events. This provides good prospects for IceCube to detect a significant event, since the background for a GRB search is close to zero.Comment: 27 pages, 13 figure