اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدNeutrino Triggered Target of Opportunity (NToO) test run with AMANDA-II and MAGIC
25
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Kilometer scale neutrino telescopes are now being constructed (IceCube) and designed (KM3NeT). While no neutrino flux of cosmic origin has been discovered so far, the first weak signals are expected to be discerned in the next few years. Multi-messenger (observations combining different kinds of emission) investigations can enhance the discovery chance for neutrinos in case of correlations. One possible application is the search for time correlations of high energy neutrinos and established signals. We show the first adaptation of a Target of Opportunity strategy to collect simultaneous data of high energy neutrinos and gamma-rays. Neutrino events with coordinates close to preselected candidate sources are used to alert gamma-ray observations. The detection of a positive coincidence can enhance the neutrino discovery chance. More generally, this scheme of operation can increase the availability of simultaneous observations. If cosmic neutrino signals can be established, the combined observations will allow time correlation studies and therefore constraints on the source modeling. A first technical implementation of this scheme involving AMANDA-II and MAGIC has been realized for few pre-selected sources in a short test run (Sept. to Dec. 2006), showing the feasability of the concept. Results from this test run are shown.
قيم البحث
اقرأ أيضاً
We investigate the capability of the Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) in performing Target-of-Opportunity (ToO) neutrino observations. POEMMA will detect tau neutrinos via Cherenkov radiation from their upward-moving extensive a
ir showers. POEMMA will be able to quickly slew ($90^{circ}$ in 500 s) to the direction of an astrophysical source, which in combination with its orbital speed will provide it with unparalleled capability to follow up transient alerts. We calculate POEMMAs transient sensitivity for two observational modes for its two satellites (ToO-stereo and ToO-dual) and investigate variations in neutrino sensitivity across the sky arising from POEMMAs orbit. We explore separate scenarios for long ($sim 10^{6}$ s) and short ($sim 10^3$ s) bursts, accounting for intrusion from the Sun and the Moon in long-duration scenarios. For long bursts, POEMMA will improve the average neutrino sensitivity above 300 PeV by up to a factor of 7 with respect to existing experiments (e.g., IceCube, ANTARES, and Pierre Auger), reaching the level of model predictions for neutrino fluences at these energies from several types of long-duration astrophysical transients (e.g., binary neutron star mergers and tidal disruption events). For short bursts in the optimal case, POEMMA will improve the sensitivity over existing experiments by at least an order of magnitude above 100 PeV. POEMMAs orbit and rapid slewing will provide access to the full celestial sky, including regions not accessible to ground-based experiments. Finally, we discuss the prospects for detecting neutrinos from candidate astrophysical neutrino sources in the nearby universe. Our results demonstrate that with its improved neutrino sensitivity at ultra-high energies and unique full-sky coverage, POEMMA will be an essential component in an expanding multi-messenger network.
A few times a century, a core collapse supernova (CCSN) occurs in our galaxy. When such galactic CCSNe happen, over 99% of its gravitational binding energy is released in the form of neutrinos. Over a period of tens of seconds, a powerful neutrino fl
ux is emitted from the collapsing star. When the exploding shock wave finally reaches the surface of the star, optical photons escaping the expanding stellar envelope leave the star and eventually arrive at Earth as a visible brightening. Crucially, although the neutrino signal is prompt, the time to the shock wave breakout can be minutes to many hours later. This means that the neutrino signal will serve as an alert, warning the optical astronomy community the light from the explosion is coming. Quickly identifying the location of the supernova on the sky and disseminating it to the all available ground and spaced-based instruments will be critical to learn as much as possible about the event. Some neutrino experiments can report pointing information for these galactic CCSNe. In particular, the Super-Kamiokande experiment can point to a few degrees for CCSNe near the center of our galaxy. A CCSN located 10 kpc from Earth is expected to result in a pointing resolution on the order of 3 degrees. LSSTs field of view (FOV) is well matched to this initial search box. LSSTs depth is also uniquely suited for identifying CCSNe even if they fail or are obscured by the dust of the galactic plane. This is a proposal to, upon receipt of such an alert, prioritize the use of LSST for a full day of observing to continuously monitor a pre-identified region of sky and, by using difference imaging, identify and announce the location of the supernova.
The field of high energy neutrino astrophysics is entering an exciting new phase as two new large-scale observatories prepare to come on line. Both DUMAND (Deep Underwater Muon and Neutrino Detector) and AMANDA (Antarctic Muon and Neutrino Detector)
had major deployment efforts in 12/93--1/94. Results were mixed, with both projects making substantial progress, but encountering setbacks that delayed full-scale operation. The achievements, status, and plans (as of 10/94) of these two projects will be discussed.
The discovery of the electromagnetic counterparts to the binary neutron star merger GW170817 has opened the era of GW+EM multi-messenger astronomy. Exploiting this breakthrough requires increasing samples to explore the diversity of kilonova behaviou
r and provide more stringent constraints on the Hubble constant, and tests of fundamental physics. LSST can play a key role in this field in the 2020s, when the gravitational wave detector network is expected to detect higher rates of merger events involving neutron stars ($sim$10s per year) out to distances of several hundred Mpc. Here we propose comprehensive target-of-opportunity (ToOs) strategies for follow-up of gravitational-wave sources that will make LSST the premiere machine for discovery and early characterization for neutron star mergers and other gravitational-wave sources.
We present simulated observations to assess the ability of LSST and the WFD survey to detect and characterize kilonovae - the optical emission associated with binary neutron star (and possibly black hole - neutron star) mergers. We expand on previous
studies in several critical ways by exploring a range of kilonova models and several choices of cadence, as well as by evaluating the information content of the resulting light curves. We find that, depending on the precise choice of cadence, the WFD survey will achieve an average kilonova detection efficiency of $approx 1.6-2.5%$ and detect only $approx 3-6$ kilonovae per year. The detected kilonovae will be within the detection volume of Advanced LIGO/Virgo (ALV). By refitting the best resulting LSST light curves with the same model used to generate them we find the model parameters are generally weakly constrained, and are accurate to at best a factor of $2-3$. Motivated by the finding that the WFD will yield a small number of kilonova detections, with poor light curves and marginal information content, and that the detections are in any case inside the ALV volume, we argue that target-of-opportunity follow-up of gravitational wave triggers is a much more effective approach for kilonova studies. We outline the qualitative foundation for such a program with the goal of minimizing the impact on LSST operations. We argue that observations in the $gz$-bands with a total time investment per event of $approx 1.5$ hour per 10 deg$^2$ of search area is sufficient to rapidly detect and identify kilonovae with $gtrsim 90%$ efficiency. For an estimated event rate of $sim20$ per year visible to LSST, this accounts for $sim1.5%$ of the total survey time. In this regime, LSST has the potential to be a powerful tool for kilonovae discovery, with detected events handed off to other narrow-field facilities for further monitoring.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
