OCTOCAM researchers will be able to use gamma-ray bursts to explore the earliest star formation events in the Universe ( Figure 1 ). It will also be ideal for following up and characterizing kilonova signatures of neutron star mergers , and likely counterparts of gravitational wave sources
OCTOCAM will allow effective broadband timing studies or reverberation mapping of X-ray binaries and active galactic nuclei ( AGN ) to constrain the physical size of the emission regions around their black holes , measure the mass of their black holes , and give new insights into accretion physics near the event horizon . For AGN , the wide wavelength coverage will allow observers to study these systems over a broad redshift range . OCTOCAM will also be able to make a significant impact in the studies of tidal disruption events ( TDEs ) — material being blown away from a black hole after it rips a star apart . Rapid broadband follow-up observations will also provide unparalleled probes of the regions close to the black hole , and ultimately allow measuring their mass and possibly their spin .
Simultaneous spectral coverage is also crucial for characterizing variable , but non-transient , objects . Such objects include asteroids where the rotation affects the colors derived if the observations are not obtained at the same time , and pre-main sequence stellar objects where star spots and accretion disks can heavily affect the derived colors . OCTOCAM ’ s fieldof-view will ensure suitable reference objects for any region observed . Having simultaneous imaging in all
of OCTOCAM ’ s eight bands enables users to determine the photometric redshift of high z objects , making the instrument efficient in rapidly identifying drop-out objects across the full field-of-view .
OCTOCAM has a strong and diverse science team led by Project Scientist Alexander van der Horst from George Washington University . Many other science cases were identified for OCTOCAM ; for further details see our website here .
OCTOCAM Instrument Design
Each of OCTOCAM ’ s eight arms is an imaging spectrograph , based on the use of highefficiency dichroics to split the light . The
Figure 1 . Photometry and spectroscopy of the most distant spectroscopically confirmed GRB to date ( Tanvir et al ., Nature , 461 : 1254 , 2009 ). The spectrum shows there is little dust in the host galaxy , consistent with a low metallicity . OCTOCAM will be an ideal tool for obtaining similar data sets very efficiently .
Figure 2 . Spectra of the Trans- Neptunian dwarf planet Eris with deep absorption features due to CH 4 ice ( Alvarez- Candal et al ., A & A , 532 : A130 , 2011 ), and the centaur 2008 YB3 with no apparent absorption features ( Pinilla-Alonso et al . , A & A , 550 : A13 , 2013 ). Also shown are the approximate positions and width of some photometric filters of OCTOCAM .
April 2017 GeminiFocus
17