Multicolor photometry of field galaxies to B = 24

Koo, David C.

doi:10.1086/164805

Cited by 93 publications

(88 citation statements)

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“…It is tempting to conjecture that CDMdominated galaxies (mostly dwarf galaxies) at moderate redshift become the low surface brightness galaxies (LSBGs) in the local universe (Bothun et al 1987;McGaugh 1992). We suggest that the moderate-redshift faint blue compact objects (FBOs; Koo 1986;Tyson 1988;Cowie et al 1988) are CDMdominated dwarf galaxies undergoing initial starbursts at z ∼ and subsequently expand to become the LSBGs seen today. 1.0 There are several pieces of observational data that together provide evidence consistent with this scenario.…”

Section: More On Small Scales: Dwarf Galaxies Low Surface Brightnessmentioning

confidence: 91%

Decaying Cold Dark Matter Model and Small-Scale Power

Cen¹

2001

The Astrophysical Journal

111

134

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The canonical cosmological constant-dominated cold dark matter model (LCDM) may possess too much power on small scales at , manifested as central overconcentration of dark matter and overabundance of dwarf z p 0 galaxies. We suggest an alternative model, LDCDM, where one-half of the cold dark matter particles decay into relativistic particles by . The model successfully lowers the concentration of dark matter in dwarf galaxies z p 0 as well as in large galaxies like our own at low redshift while simultaneously retaining the virtues of the LCDM model. The model solves the problem of overproduction of small dwarf galaxies in the LCDM, not by removing them but by identifying them with failed, "dark" galaxies, where star formation is quenched as a result of dark matter evaporation and consequent halo expansion. A dramatic difference between the LDCDM model and other proposed variants of the LCDM model is that the small-scale power at high redshift ( ) in the LDCDM z 1 2 model is enhanced compared to the LCDM model. A COBE-and cluster-normalized LDCDM model can be constructed with the following parameters:, and . A clean test of this model can be made by measuring the evolution of the gas fraction n p 1.0 j p 1.06 8 in clusters. The prediction is that the gas fraction should decrease with redshift and is smaller by 31% at z p than at . X-ray and Sunyaev-Zeldovich effect observations should provide such a test. 1 z p 0 Subject headings: cosmic microwave background -cosmology: theory -dark mattergalaxies: formation -large-scale structure of universe

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Section: More On Small Scales: Dwarf Galaxies Low Surface Brightnessmentioning

confidence: 91%

Decaying Cold Dark Matter Model and Small-Scale Power

Cen¹

2001

The Astrophysical Journal

111

134

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“…(hereafter KK data see Kron 1980, Koo 1986, Kron et al 1995. It is based on about 1.5 square degrees of (KPNO 4-meter telescope, 1-hour exposure) UJFN plates (UJFN lters correspond approximately to SDSS ugri lters, respectively, see Appendix A) in four regions of the sky which sample a variety of galactic locations (l,b).…”

Section: The Datamentioning

confidence: 99%

“…We will nd about 17,000 additional quasars in the southern strips, and maybe a few more at very high redshift. Use was made of two data sets: the star and quasar simulated test data generated by D o n S c hneider, and the data from UJFN plate surveys by Koo (1986) and Kron (1980). This data was compared to results from the Palomar-Green Survey and a recent s u r v ey by P at Osmer and collaborators.…”

Section: Introductionmentioning

confidence: 99%

Quasar target selection fiber efficiency

Newberg¹,

Yanny²

1996

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We present estimates of the e ciency for nding QSOs as a function of limiting magnitude and galactic latitude. From these estimates, we h a ve formulated a target selection strategy that should net 80 000 QSOs in the north galactic cap with an ave r a g e o f 7 0 bers per plate, not including bers reserved for high-redshift quasars. With this plan, we expect 54% of the targets to be QSOs. The North Galactic Cap is divided into two zones of high and low stellar density. W e use about ve times as many bers for QSO candidates in the half of the survey with the lower stellar density a s w e use in the half with higher stellar density. The current plan assigns 15% of the bers to FIRST radio sources if these are not available, those bers would be allocated to lower probability QSO sources, dropping the total number of QSOs by a small factor (5%). We will nd about 17,000 additional quasars in the southern strips, and maybe a few more at very high redshift. Use was made of two data sets: the star and quasar simulated test data generated by D o n S c hneider, and the data from UJFN plate surveys by Koo (1986) and Kron (1980). This data was compared to results from the Palomar-Green Survey and a recent s u r v ey by P at Osmer and collaborators.

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“…For comparison purposes, we also plot I-band number counts found from surveys by Hall & Mackay (1984), Koo (1986), Tyson (1988), Lilly, Cowie, & Gardner (1991), and Gardner et al (1996). The number counts of these various surveys agree with the number counts from the WFPC2 flanking fields.…”

Section: Wfpc2mentioning

confidence: 70%

The Hubble Deep Field South Flanking Fields

Lucas

Baum

Brown

et al. 2003

The Astronomical Journal

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As part of the Hubble Deep Field South program, a set of shorter two-orbit observations were obtained of the area adjacent to the deep fields. The WFPC2 flanking fields cover a contiguous solid angle of 48 arcmin 2 . Parallel observations with the STIS and NICMOS instruments produce a patchwork of additional fields with optical and near-infrared (1.6 lm) response. Deeper parallel exposures with WFPC2 and NICMOS were obtained when STIS observed the NICMOS deep field. These deeper fields are offset from the rest, and an extended low surface brightness object is visible in the deeper WFPC2 flanking field. In this data paper, which serves as an archival record of the project, we discuss the observations and data reduction and present SExtractor source catalogs and number counts derived from the data. Number counts are broadly consistent with previous surveys from both ground and space. Among other things, these flanking field observations are useful for defining slit masks for spectroscopic follow-up over a wider area around the deep fields, for studying large-scale structure that extends beyond the deep fields, for future supernova searches, and for number counts and morphological studies, but their ultimate utility will be defined by the astronomical community.

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Multicolor photometry of field galaxies to B = 24

Cited by 93 publications

References 0 publications

Decaying Cold Dark Matter Model and Small-Scale Power

Decaying Cold Dark Matter Model and Small-Scale Power

Quasar target selection fiber efficiency

The Hubble Deep Field South Flanking Fields

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