101 research outputs found
PS2: Managing the next step in the Pan-STARRS wide field survey system
The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) is
unique among the existing or planned major ground-based optical survey systems
as the only "distributed aperture" system. The concept of increasing system
\'etendue by replicating small telescopes and digital cameras presents both
management opportunities and challenges. The focus in this paper is on
management lessons learned from PS1, and how those have been used to form the
management plan for PS2. The management plan components emphasized here include
technical development, financial and schedule planning, and critical path and
risk management. Finally, the status and schedule for PS2 are presented.Comment: Paper presented at SPIE 2012 Astronomical Telescopes and
Instrumentation, to be published in conference proceedings (8449-28
trans-GZK Cosmic Rays: Strings, Black Holes, Neutrinos, or All Three?
We review the scenario in which ``strongly interacting neutrinos'' are
responsible for inducing airshowers with inferred energies
eV. This possibility arises naturally in string excitation models having a
unification scale effectively decoupled from the Planck scale. We then show
that phenomenological quantum gravity considerations reveal an equivalency of
``mini-black hole'' and strongly interacting neutrino pictures for explaining
trans-GZK events. This equivalence can be exploited to predict single particle
inclusive distributions. The resulting observable consequences in airshower
development are studied using the Adaptive Longitudinal Profile Shower (ALPS)
simulation.Comment: Talk presented at Cosmic Ray International Seminar (CRIS), Catania,
Sicily, 2004; 6 pages, 6 figure
Signatures of Precocious Unification in Orbiting Detectors
It has been conjectured that the string and unification scales may be
substantially lower than previously believed, perhaps a few TeV. In scenarios
of this type, orbiting detectors such OWL or AIRWATCH can observe spectacular
phenomena at trans-GZK energies. We explore measurable signatures of the
hypothesis that trans-GZK air showeres (``anomalous showers'') are originated
by strongly interacting neutrinos. The results of a MC simulation of such air
showers is described. A distinction between proton induced and ``anomalous''
showers becomes possible once a substantial sample of trans-GZK showers will be
available.Comment: LaTeX 2e, 14 pages, 5 figures. Revised and expanded version: MC
rerun, figures redrawn, text revised and expande
Brown Dwarfs in Young Moving Groups from Pan-STARRS1. I. AB Doradus
Substellar members of young (150 Myr) moving groups are valuable
benchmarks to empirically define brown dwarf evolution with age and to study
the low-mass end of the initial mass function. We have combined Pan-STARRS1
(PS1) proper motions with opticalIR photometry from PS1, 2MASS and
to search for substellar members of the AB Dor Moving Group
within 50 pc and with spectral types of late-M to early-L,
corresponding to masses down to 30 M at the age of the group
(125 Myr). Including both photometry and proper motions allows us to
better select candidates by excluding field dwarfs whose colors are similar to
young AB~Dor Moving Group members. Our near-IR spectroscopy has identified six
ultracool dwarfs (M6L4; 30100 M) with intermediate
surface gravities (INT-G) as candidate members of the AB Dor Moving Group. We
find another two candidate members with spectra showing hints of youth but
consistent with field gravities. We also find four field brown dwarfs
unassociated with the AB Dor Moving Group, three of which have INT-G gravity
classification. While signatures of youth are present in the spectra of our
125 Myr objects, neither their nor colors are
significantly redder than field dwarfs with the same spectral types, unlike
younger ultracool dwarfs. We also determined PS1 parallaxes for eight of our
candidates and one previously identified AB Dor Moving Group candidate.
Although radial velocities (and parallaxes, for some) are still needed to fully
assess membership, these new objects provide valuable insight into the spectral
characteristics and evolution of young brown dwarfs.Comment: ApJ, accepte
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