X-Ray View of Star-Formation and Accretion in Normal Galaxies

Summary

Spectra for the optical counterparts of Chandra x-ray targets in a 7,650 survey area

Finding Targets

An object whose ANCILLARY_TARGET1 value include one or more of the bitmasks in the following table was targeted for spectroscopy as part of this ancillary target program. See SDSS-III bitmasks to learn how to use these values to identify objects in this ancillary target program.

Program (bit name)	Bit Number	Target density (deg^–2)
CHANDRAV1	57	0.2

Description

The extended wavelength coverage and improved throughput of BOSS relative to SDSS enable studies of the relationship between star formation and black hole accretion in galaxies using the key diagnostic H_α/N[II] to z ~0.49.

Primary contact

Daryl Haggard
Northwestern University
dhaggard -at- northwestern.edu

Other contacts

Paul J. Green, Niel Brandt, Adam Myers, Anca Constantin

Target Selection Details

For this study, a target list was derived from the matched Chandra Source Catalog (CSC; version 1; Evans et al. 2010) and SDSS DR7 photometric catalogs.
High quality matches underwent visual inspection in X-ray and optical imaging and were required to have positional matches between the SDSS DR7 catalog and the CSC as defined by the Rots et al. (2009) matching method that incorporates positions, positional errors, and sky coverage.
- Matches with Bayesian probability < 0.5 suffer from a larger number of multiple matches and are discarded.
Targets were required to have model magnitude 16.5 < r < 20.75
Targets were also required to have Chandra off-axis angles < 10'.
Objects with existing SDSS spectroscopy, proper motions from Munn et al. (2004, 2008) exceeding 11 mas/year (selection criteria are described further in Haggard et al. 2010), or poor-quality X-ray measurements are removed from the sample.

Because only sources with Chandra coverage were included, the target have a non-uniform distribution over the DR7 footprint. To avoid overlap between the targets selected for this program and the program "Remarkable X-ray Source Populations", the target lists were cross-correlated (using a 2" match radius) and 754 duplicates were removed from this program designation.

REFERENCES

Evans, I. N., et al., 2010, ApJS, 189, 37 doi:10.1088/0067-0049/189/1/37
Rots, A., et al., 2009, in Chandra's First Decade of Discovery, ed. S. Wolk, A. Fruscione, D. Swartz
Munn, J. A., et al., 2004, AJ, 127, 3034 doi:10.1086/383292
Munn, J. A., et al., 2008, AJ, 136, 895 doi:10.1088/0004-6256/136/2/895
Haggard, D., et al., 2010, ApJ, 723, 1447 doi:10.1088/0004-637X/723/2/1447