Pan-STARRS: A Large Synoptic Survey Telescope Array

Dark Matter (DM) direct detection experiments usually assume the simplest possible 'Standard Halo Model' for the Milky Way (MW) halo in which the velocity distribution is Maxwellian. This model assumes that the MW halo is an isotropic, isothermal sphere, hypotheses that are unlikely to be valid in reality. An alternative approach is to derive a self-consistent solution for a particular mass model of the MW (i.e. obtained from its gravitational potential) using the Eddington formalism, which assumes isotropy. In this paper we extend this approach to incorporate an anisotropic phase-space distribution function. We perform Bayesian scans over the parameters defining the mass model of the MW and parameterising the phase-space density, implementing constraints from a wide range of astronomical observations. The scans allow us to estimate the precision reached in the reconstruction of the velocity distribution (for different DM halo profiles). As expected, allowing for an anisotropic velocity tensor increases the uncertainty in the reconstruction of f (v), but the distribution can still be determined with a precision of a factor of 4-5. The mean velocity distribution resembles the isotropic case, however the amplitude of the high-velocity tail is up to a factor of 2 larger. Our results agree with the phenomenological parametrization proposed in Mao et al. (2013) as a good fit to N-body simulations (with or without baryons), since their velocity distribution is contained in our 68% credible interval.

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“…the GAIA satellite [117,118]) or by the new data releases of already operational surveys, e.g. SEGUE [119], RAVE [120] and PanSTARRS [121].…”

Section: Discussionmentioning

confidence: 99%

Self-consistent phase-space distribution function for the anisotropic dark matter halo of the Milky Way

Fornasa

Green

2014

Phys. Rev. D

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“…The EM transients accompanying GW events are possible sources for current or upcoming telescopes, e.g. PTF [15], PanSTARRS [16], or LSST [17]. Moreover, compact binary mergers could be integral to solving several outstanding astrophysical puzzles, such as determining the progenitors of short-hard gamma ray bursts (see e.g.…”

Section: Introductionmentioning

confidence: 99%

Relativistic simulations of eccentric binary neutron star mergers: One-arm spiral instability and effects of neutron star spin

et al. 2016

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We perform general-relativistic hydrodynamical simulations of dynamical capture binary neutron star mergers, emphasizing the role played by the neutron star spin. Dynamical capture mergers may take place in globular clusters, as well as other dense stellar systems, where most neutron stars have large spins. We find significant variability in the merger outcome as a function of initial neutron star spin. For cases where the spin is aligned with the orbital angular momentum, the additional centrifugal support in the remnant hypermassive neutron star can prevent the prompt collapse to a black hole, while for antialigned cases the decreased total angular momentum can facilitate the collapse to a black hole. We show that even moderate spins can significantly increase the amount of ejected material, including the amount unbound with velocities greater than half the speed of light, leading to brighter electromagnetic signatures associated with kilonovae and interaction of the ejecta with the interstellar medium. Furthermore, we find that the initial neutron star spin can strongly affect the already rich phenomenology in the postmerger gravitational wave signatures that arise from the oscillation modes of the hypermassive neutron star. In several of our simulations, the resulting hypermassive neutron star develops the one-arm (m = 1) spiral instability, the most pronounced cases being those with small but non-negligible neutron star spins. For longlived hypermassive neutron stars, the presence of this instability leads to improved prospects for detecting these events through gravitational waves, and thus may give information about the neutron star equation of state.

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“…We have developed an algorithm to answer this question, and here we present the results of a proof-of-concept demonstration applied to four different telescopes including SubaruHyperSuprimeCam (HSC) 1 (Miyazaki et al 2012) , CTIO-Dark Energy Camera (DEC) (Bernstein et al 2012), Pan-Starrs 2 (Kaiser et al 2002), and Palomar Transient Factory (PTF) (Law et al 2009) for three different simulated GW events. This algorithm takes as inputs GW sky localization information, and returns a guidance strategy for time allocation and telescope pointing for a given EM telescope.…”

Section: Introductionmentioning

confidence: 99%

Maximizing the Detection Probability of Kilonovae Associated With Gravitational Wave Observations

Chan

Messenger

et al. 2017

ApJ

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Estimates of the source sky location for gravitational wave signals are likely span areas ranging up to hundreds of square degrees or more, making it very challenging for most telescopes to search for counterpart signals in the electromagnetic spectrum. To boost the chance of successfully observing such counterparts, we have developed an algorithm which optimizes the number of observing fields and their corresponding time allocations by maximizing the detection probability. As a proofof-concept demonstration, we optimize follow-up observations targeting kilonovae using telescopes including CTIO-Dark Energy Camera, Subaru-HyperSuprimeCam, Pan-STARRS and Palomar Transient Factory. We consider three simulated gravitational wave events with 90% credible error regions spanning areas from ∼30 deg 2 to ∼300 deg 2 . Assuming a source at 200 Mpc, we demonstrate that to obtain a maximum detection probability, there is an optimized number of fields for any particular event that a telescope should observe. To inform future telescope design studies, we present the maximum detection probability and corresponding number of observing fields for a combination of limiting magnitudes and fields-of-view over a range of parameters. We show that for large gravitational wave error regions, telescope sensitivity rather than field-of-view, is the dominating factor in maximizing the detection probability.

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Pan-STARRS: A Large Synoptic Survey Telescope Array

Cited by 589 publications

References 5 publications

Self-consistent phase-space distribution function for the anisotropic dark matter halo of the Milky Way

Self-consistent phase-space distribution function for the anisotropic dark matter halo of the Milky Way

Relativistic simulations of eccentric binary neutron star mergers: One-arm spiral instability and effects of neutron star spin

Maximizing the Detection Probability of Kilonovae Associated With Gravitational Wave Observations

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