scholarly journals A search for massive compact halo objects in our galaxy

1991 ◽  
Author(s):  
D. P. Bennett ◽  
C. Alcock ◽  
T. Axelrod ◽  
K. Cook ◽  
H. Park ◽  
...  
Keyword(s):  
Massive Compact Halo Objects

scholarly journals A Dual CCD Mosaic Camera System Searching for Massive Compact Halo Objects (Machos)

1995 ◽  
Vol 167 ◽  
pp. 357-357
Author(s):  
Kem H. Cook
Keyword(s):  
Focal Plane ◽  
Preliminary Analysis ◽  
Milky Way ◽  
Large Magellanic Cloud ◽  
Variable Stars ◽  
Magellanic Cloud ◽  
Camera System ◽  
Massive Compact Halo Objects ◽  
Photometric Measurements ◽  
Analysis System

The Macho Collaboration uses a dedicated 1.27-m telescope (The Great Melbourne Telescope) at Mount Stromlo to make photometric measurements of tens of millions of stars per night searching for the gravitational microlensing signature of MACHOs in the halo and disk of the Milky Way. A prime focus corrector and dichroic beamsplitter provide red (6300–7800 å) and blue (4500–6300 å) foci with one degree fields. A two by two mosaic of 2048 × 2048 pixel CCDs in each focal plane provides simultaneous images of 0.5 square degrees. By August of 1994, more than 20,000, 32 Megapixel images will have been collected of fields in the Large Magellanic Cloud (LMC), Small Magellanic Cloud and the bulge of the Milky Way. We have implemented an online analysis system which produces photometric reductions of a night's data (five Gbyte of images) within 24 hours. This system allows us to identify and follow interesting events in real-time. In this search, we have identified more than 60,000 variable stars, and a preliminary analysis of their types and distribution will be presented. Microlensing events toward the LMC and the bulge have been discovered and detection efficiencies are being calculated to constrain the MACHO content of the Milky Way's halo.

Are Axidilaton Stars Massive Compact Halo Objects?

2001 ◽  
Vol 33 (5) ◽  
pp. 805-813 ◽  
Author(s):  
Eckehard W. Mielke ◽  
Franz E. Schunck
Keyword(s):  
Massive Compact Halo Objects

scholarly journals Relics of cosmic quark-hadron phase transition and massive compact halo objects

2003 ◽  
Vol 715 ◽  
pp. 827c-830c
Author(s):  
Shibaji Banerjee ◽  
Abhijit Bhattacharyya ◽  
Sanjay K. Ghosh ◽  
Sibaji Raha ◽  
Bikash Sinha ◽  
...  
Keyword(s):  
Phase Transition ◽  
Hadron Phase ◽  
Massive Compact Halo Objects

scholarly journals Massive Compact Halo Objects from the relics of the cosmic quark-hadron transition

2003 ◽  
Vol 340 (1) ◽  
pp. 284-288 ◽  
Author(s):  
S. Banerjee ◽  
A. Bhattacharyya ◽  
S. K. Ghosh ◽  
S. Raha ◽  
B. Sinha ◽  
...  
Keyword(s):  
Massive Compact Halo Objects

scholarly journals The CCD Array Camera for the Macho Project

1994 ◽  
Vol 161 ◽  
pp. 67-71
Author(s):  
S. Marshall
Keyword(s):  
Imaging System ◽  
High Surface ◽  
Large Magellanic Cloud ◽  
Compact Objects ◽  
Science Data ◽  
Simultaneous Imaging ◽  
Ccd Array ◽  
Massive Compact Halo Objects ◽  
Readout Time ◽  
The Galaxy

We have developed an astronomical imaging system tailored to our search for gravitational microlensing by compact objects in the halo and disk of the Galaxy. The challenge of detecting rare microlensing events is to monitor ∼ 10 million stars per night and distinguish genuine events from other sources of variability. The Large Magellanic Cloud and the Galactic bulge provide the high surface density of resolvable stars necessary for this task. A dedicated 50 inch telescope at Mt. Stromlo Observatory has been producing science data since the fall of 1992. Our system incorporates eight 2048 × 2048 CCDs into two focal planes for simultaneous imaging in two passbands (4500–6300 and 6300–8100 å). Each focal plane consists of four ‘edge-buttable’ CCDs in a custom mounted 2 × 2 array. The 0.62 arcsecond pixel scale (15 μm) yields a 40 × 40 arcminute square field of view in each frame. A sophisticated point spread fitting photometry package extracts up to 600,000 useful magnitudes per color per frame. The data collection rate we need is obtained by simultaneously reading out all sixteen CCD outputs (two per chip) at 34 KHz with 16 bit digitization. With exposure times of 150–300 seconds and a 70 second readout time we can collect up to 100 fields per night. These rates are designed to allow us to detect or rule out massive compact halo objects (MACHOs) in the 10−6–101 M ⊙ range.

The search for massive compact halo objects

2008 ◽  
pp. 156-162
Author(s):  
C. Alcock ◽  
T. S. Axelrod ◽  
D. P. Bennett ◽  
K. H. Cook ◽  
H. -S. Park ◽  
...  
Keyword(s):  
Massive Compact Halo Objects
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