1,865 research outputs found
Seeing and Exploring the Universe Resource Guide
This guide provides an overview of 16 NASA missions studying the structure and evolution of the Universe. A description of the science and educational programs for each mission is provided, along with a list of other relevant resources and websites. The following missions are described in the guide: Advanced Composition Explorer (ACE), Astro-E2, Chandra, Cosmic Hot Interstellar Plasma Spectrometer (CHIPS), Constellation X-ray Mission (CON-X), Galaxy Evolution Explorer (GALEX) Gamma-Ray Large Area Space Telescope (GLAST) Gravity Probe-B (GP-B), High Energy Transient Explorer 2 (HETE-2), International Gamma-Ray Astrophysics Laboratory (INTEGRAL), Laser Interferometer Space Antenna (LISA), Microwave Anisotropy Probe (MAP), Rossi X-ray Timing Explorer (RXTE), Submillimeter Wave Astronomy Satellite (SWAS), Swift, and X-ray Multi-Mirror-Newton Mission (XMM-Newton). Educational levels: Primary elementary, Intermediate elementary, Middle school, High school
Colloquium: Multimessenger astronomy with gravitational waves and high-energy neutrinos
Many of the astrophysical sources and violent phenomena observed in our Universe are potential emitters of gravitational waves and high-energy cosmic radiation, including photons, hadrons, and presumably also neutrinos. Both gravitational waves (GW) and high-energy neutrinos (HEN) are cosmic messengers that may escape much denser media than photons. They travel unaffected over cosmological distances, carrying information from the inner regions of the astrophysical engines from which they are emitted (and from which photons and charged cosmic rays cannot reach us). For the same reasons, such messengers could also reveal new, hidden sources that have not been observed by conventional photon-based astronomy. Coincident observation of GWs and HENs may thus play a critical role in multimessenger astronomy. This is particularly true at the present time owing to the advent of a new generation of dedicated detectors: the neutrino telescopes IceCube at the South Pole and ANTARES in the Mediterranean Sea, as well as the GW interferometers Virgo in Italy and LIGO in the United States. Starting from 2007, several periods of concomitant data taking involving these detectors have been conducted. More joint data sets are expected with the next generation of advanced detectors that are to be operational by 2015, with other detectors, such as KAGRA in Japan, joining in the future. Combining information from these independent detectors can provide origin always of constraining the physical processes driving the sources and also help confirm the astrophysical origin of a GW or HEN signal in case of coincident observation. Given the complexity of the instruments, a successful joint analysis of this combined GW and HEN observational data set will be possible only if the expertise and knowledge of the data is shared between the two communities. This Colloquium aims at providing an overview of both theoretical and experimental state of the art and perspectives for GW and HEN multimessenger astronomy
Pathway to the Square Kilometre Array - The German White Paper -
The Square Kilometre Array (SKA) is the most ambitious radio telescope ever
planned. With a collecting area of about a square kilometre, the SKA will be
far superior in sensitivity and observing speed to all current radio
facilities. The scientific capability promised by the SKA and its technological
challenges provide an ideal base for interdisciplinary research, technology
transfer, and collaboration between universities, research centres and
industry. The SKA in the radio regime and the European Extreme Large Telescope
(E-ELT) in the optical band are on the roadmap of the European Strategy Forum
for Research Infrastructures (ESFRI) and have been recognised as the essential
facilities for European research in astronomy.
This "White Paper" outlines the German science and R&D interests in the SKA
project and will provide the basis for future funding applications to secure
German involvement in the Square Kilometre Array.Comment: Editors: H. R. Kl\"ockner, M. Kramer, H. Falcke, D.J. Schwarz, A.
Eckart, G. Kauffmann, A. Zensus; 150 pages (low resolution- and colour-scale
images), published in July 2012, language English (including a foreword and
an executive summary in German), the original file is available via the MPIfR
homepag
All-sky Medium Energy Gamma-ray Observatory: Exploring the Extreme Multimessenger Universe
The All-sky Medium Energy Gamma-ray Observatory (AMEGO) is a probe class mission concept that will provide essential contributions to multimessenger astrophysics in the late 2020s and beyond. AMEGO combines high sensitivity in the 200 keV to 10 GeV energy range with a wide field of view, good spectral resolution, and polarization sensitivity. Therefore, AMEGO is key in the study of multimessenger astrophysical objects that have unique signatures in the gamma-ray regime, such as neutron star mergers, supernovae, and flaring active galactic nuclei. The order-of-magnitude improvement compared to previous MeV missions also enables discoveries of a wide range of phenomena whose energy output peaks in the relatively unexplored medium-energy gamma-ray band
Search for Multi-Messenger Transients with IceCube and ZTF
Das IceCube Neutrino Observatory, das größte Neutrino-Observatorium der Welt, entdeckte
2013 erstmals einen Fluss hochenergetischer Neutrinos. Diese Neutrinos müssen
von astrophysikalischen Beschleunigern erzeugt werden, aber ihr genauer Ursprung ist
bisher unbekannt. Vorgeschlagene Neutrinoquellen sind Gezeitenkatastrophen (Tidal
Disruption Events, TDEs), Ereignisse bei denen Sterne zerfallen, wenn sie supermassiven
Schwarzen Löchern zu nahe kommen. In dieser Doktorarbeit wurde erstmals nach
Korrelationen zwischen Neutrinos und TDEs gesucht, wobei eine Zusammenstellung
veröffentlichter TDEs und ein IceCube-Datensatz von einer Million Myon-Neutrinos mit
GeV-PeV-Energien von verwendet wurde. Es wurde keine signifikante Korrelation gefunden,
sodass der Beitrag von TDEs ohne relativistische Jets auf 0-38,0% des gesamten
astrophysikalischen Neutrinoflusses begrenzt werden kann. Der Beitrag von TDEs mit
relativistischen Jets wurde auf 0-3,0% des Gesamtflusses begrenzt. IceCube veröffentlicht
auch hochenergetische (>100 TeV) Myon-Neutrino-Ereignisse in Form von automatischen,
öffentlichen Echtzeit-‘Neutrinoalerts’. Im Rahmen dieser Arbeit wurde die Lokalisierung
von 22 solcher Neutrinoalerts mit dem optischen Zwicky Transient Facility (ZTF) Teleskop
beobachtet, um nach möglichen elektromagnetischen Gegenstücken zu Neutrinos zu
suchen. Mit diesem Neutrino-Nachfolgebeobachtungsprogramm wurde die helle TDE
AT2019dsg als mutmaßliche Neutrinoquelle identifiziert. Die Wahrscheinlichkeit, solch
eine helle TDE zufällig zu finden, beträgt 0,2%. Die Assoziation bedeutet, dass TDEs 3-100%
der astrophysikalischen Neutrino-Alerts von IceCube ausmachen. Zusammengenommen
deuten diese beiden Ergebnisse darauf hin, dass TDEs einen subdominanten Anteil des
astrophysikalischen Neutrinoflusses bei hohen Energien emittieren. Die Assoziation des
Neutrinoalerts IC191001A mit AT2019dsg ist erst das zweite Mal, dass ein hochenergetisches
Neutrino mit einer mutmaßlichen astrophysikalischen Quelle in Verbindung gebracht
werden konnte.The IceCube Neutrino Observatory, the world’s largest neutrino observatory, first discovered
a flux of high-energy neutrinos in 2013. These neutrinos must be produced by
astrophysical accelerators, but their exact origin remains unknown. One proposed source
of neutrinos are Tidal Disruption Events (TDEs), which occur when stars disintegrate
after passing sufficiently close to supermassive black holes. In this thesis, the first search
for neutrino-TDE correlations was performed, using a compilation of published TDEs and
a dataset of one million muon neutrino events of GeV-PeV energies from IceCube. No
significant correlation was found, limiting the contribution of TDEs without relativistic
jets to 0-38.0% of the total astrophysical neutrino flux. The contribution of TDEs with
relativistic jets was limited to 0-3.0% of the total flux. IceCube also publishes high-energy
(>100 TeV) probable astrophysical muon neutrino events automatically, in the form of
public realtime alerts. As part of this thesis, the location of 22 such neutrino alerts were
observed by the Zwicky Transient Facility (ZTF), an optical telescope, in order to search
for possible electromagnetic counterparts to neutrinos. With this neutrino follow-up
program, the bright TDE AT2019dsg was identified as a probable neutrino source. The
probability of finding such a bright TDE by chance is 0.2%. The association implies that
TDEs contribute 3-100% of the astrophysical neutrino alerts issued by IceCube. Taken
together, these two results suggest that TDEs emit a subdominant fraction of the astrophysical
neutrino flux at high energies. The association of neutrino alert IC191001A with
AT2019dsg represents only the second time that a high-energy neutrino has been matched
to a probable astrophysical source
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