Redshift surveys

Spergel et al. 2007), but greatly exceeds the smoothed-out cosmological density of luminous matter deduced from galaxy redshift surveys, which give a luminosity density in blue light... 

The IRAS galaxies provided some of the earliest evidence from redshift surveys, and from source counts as a function of observed flux, that the spiral galaxy population has undergone evolution (ORS see Fig. 12.2). This result is analogous to similar evidence from source counts of radio galaxies and quasars, as well as quasar redshifts, and a correlation that has been observed between radio and infrared luminosity suggests that the evolution could be similar in both cases. Typical simple models for such evolution include luminosity evolution according to... 

When the light is dominated by massive stars, e.g. in starburst galaxies, the luminosity is related in turn to the rate of metal production, since virtually all processed material is ejected in the form of metals (and some helium). Thus there is a relationship between the total co-moving luminosity density, the monochromatic luminosity density (deduced from star-forming galaxy redshift surveys with appropriate corrections for absorption) in a fixed frequency bandwidth (anywhere between 912 and about 2000 A in the rest frame) and the mass going into nucleosynthesis ... 

For example, several redshift surveys, such as those performed by Huchra et al. [28], Giovanelli et al. [29], De Lapparent et al. [30], Broadhurst et al. [317], Da Costa et al. [32] and Vettolani et al. [33], have discovered massive structures such as sheets, filaments, superclusters, and voids, and show that large structures are common features of the observable universe the most significant conclusion to be drawn from all of these surveys is that the scale of the largest inhomogeneities observed is comparable with the spatial extent of the surveys themselves. 

This latter view is now widely accepted (see e.g., Wu et al. [37]), and the open question has become whether there is a transition to homogeneity on some sufficiently large scale. For example, Scaramella et al. [38] analyze the ESO Slice Project redshift survey, while Martinez et al. [39] analyze the Perseus-Pisces, the APM-Stromlo, and the 1.2-Jy IRAS redshift surveys, with both groups finding evidence for a crossover to homogeneity at large scales. In response, the Scaramella et al. analysis has been criticized on various grounds by Joyce et al. [40]. 

Figure 3.4. Cluster detection efficiency for blind redshift surveys down to 1=24. Solid line is for a 100% complete survey, dotted line is for a 50% complete survey. Dashed line is for a 33% complete survey down to 1=22.5.

Abstract. 1 present K band photometry of the objects in the spectroscopic redshift survey of [CoUess et al., 1990]. The absolute K magnitudes of the objects are consistent with the no-evolution or pure luminosity evolution models. The excess f t blue galaxies seen in the B band number counts at intermediate magnitudes are a result of a low normalization, and do not dominate the population until B 25. Extreme merging or excess dwarf models are not needed. 

Complementary observations of a larger but shallower area were obtained at the Steward 1.55m Catalina telescope as part of a K-selected redshift survey being done by BAM, MJR, and G. Bemstdn. These observations are of two 4 X 4 fields using a NICM0S3 detector with 300min integration per field to K=20. 

The IRAS satellite mission, launched in 1983, provided a more complete survey of disk and active galaxies containing dust than had been possible from optical observations. Follow-up measurements of redshifts and other properties led to significant results for cosmology and the discovery of many luminous star-forming and active galaxies enshrouded by dust. A typical spiral galaxy like our own... 

Fig. 12.4. Global co-moving star-formation rate density (assuming a Salpeter(O.l) IMF) compiled from surveys by Lilly et al. (1996), Connolly et al. (1997) and Steidel et al. (1999), assuming Einstein-de Sitter cosmology with h = 0.5. The point at zero redshift is based on an Ha survey by Gallego et al. (1995). After Pettini (1999). With kind permission of Springer Science and Business Media. Courtesy Max Pettini.

Fig. 12.6. Observable baryons in the Universe as a function of time. The curves represent the total mass density in stars (in Af0Mpc-3) from Rudnick et al. (2003) based on a survey of near-infrared selected galaxies in the Hubble Deep Field South, assuming a Salpeter(O.l) IMF. (For a Kennicutt (1983) IMF, the numbers would be approximately halved.) The points with error bars show the cosmic density of H I from DLAs and sub-DLAs at various redshifts, uncorrected for obscuration, while the point at bottom right shows the present-day density of H i clouds determined by Zwaan et al. (2005). The typical H I co-moving volume density corresponds to S2Hi — 0.7 x 10-3 (taking h = 0.65). After Peroux, Dessauges-Zavatsky, D Odorico et al. (2005).

Because cosmic shear surveys probe the dark matter distribution up to significant redshift, it is a probe of the details of the gravitational dynamics. With large scale surveys it then becomes possible to test the details of large-scale structure growth with unprecedented accuracy. 

Figure 7. Plot of the abundance of Zn against redshift for the full sample of 41 DLAs from the surveys by Pettini and collaborators. Abundances are measured on a log scale relative to the solar value shown by the broken line at [Zn/H] = 0.0 thus a point at [Zn/H] = —1.0 corresponds to a metallicity of 1/10 of solar. Upper limits, corresponding to non-detections of the Zn II lines, are indicated by downward-pointing arrows. Upward-pointing arrows denote lower limits in two cases where the Zn II lines are sufficiently strong that saturation may be important.

Figure 9. Column density-weighted metallicities of DLAs in different redshift intervals, from the surveys by Pettini et al. (1999) for Zn, and Prochaska Wolfe (2002) for Fe. The lower abundance of Fe relative to Zn probably reflects the presence of moderate amounts of dust in most DLAs (Vladilo 2002b).

The near-IR spectroscopic survey by Pettini et al. (2001) confirmed a trend which had already been suspected on the basis of the optical (rest-frame UV) data alone. When the redshifts of the interstellar absorption lines, of the nebular emission lines, and of the resonantly scattered Lya emission line are compared within the same galaxy, a systematic pattern of velocity differences emerges in all LBGs observed up to now (see Figure 30). We interpret this effect as indicative of galaxy-wide outflows, presumably driven by the supernova activity associated with the star-formation episodes. Such superwinds appear to be a common characteristic of galaxies with large rates of star formation per... 

Final confirmation came from a radio survey of binary galaxies which established redshift differences between pairs grouped around j, 2j and 3j at high confidence levels. 

It is also essential to reach arcsecond to sub-arcsecond resolution because it will break free the confusion limit that marred the Herschel survey. Moreover, such spatial resolution would sample sub-kpc structure at any redshift ( 0.8 arcsecond at z = 1 to z = 3, and even better at z < 1). 

Much attention has been paid recently to an apparent excess of faint blue galaxies observed in photometric surveys. When the models of the B band number counts are normalized at B=16, the data show an excess over the luminosity evolution models of a factor of 2 at B=22. ([Tyson, 1988], [Lilly et al., 1991]) However, the K band number counts do not show this same excess, ([Gardner et al., 1993]). The shape of the number-redshifr distribution of surveys conducted at 20 < B < 22.5 by [Broadhurst et al., 1988] and [CoUess et al., 1990] are fitted by the no-evolution model. The median redshifts of the data from these surveys, and deeper data of [Cowie et al., 1991] and [AUington-Smith et al., 1992] show no evolution as faint as B=24. Proposed explanations for the high B band number counts include massive amounts of merging at intermediate redshifts (z 0.4) ([Broadhurst et al., 1992]) and an excess population of dwarf galaxies which appears at these redshifts, but has dissipated or faded by the present epoch. ([Cowie et al., 1991])... 

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