Bernheimer 1932 (abstract)
In examining bright metagalactic clusters, Bernheimer reports finding clusters of anagalactic nebula between the Perseus and Pegasus constellations, seeming to form subsystems of a larger metagalactic cloud.
This cloud borders both the Perseus and Pisces clusters, and as more information is found regarding these clusters and infall into them from projects such as APPS, the nature of such nebula and metagalactic clouds, particularly those in observation, will be further understood.
Chincarini 1976
This paper presents new radial velocities for some galaxies in the fields of Pegasus I & II. Some observed galaxies with a radial velocity near the average for Pegasus II galaxies, suggesting the cluster may be a part of a large cloud of galaxies.
The research behind this paper required similar radio reduction processes to the APPS survey. It also similarly examines interactions between galaxies and larger structures in the universe.
McGaugh 2000:
Field galaxies with Vc 90 km*s-1 do not fit with the Tully-Fisher Relation, but by including gas mass and replacing luminosity with baryonic mass, the Baryonic Tully-Fisher method allows these galaxies to be studied more accurately.
Faint galaxies such as those we observe in this study require a different method of measurement from the TFR, making the BTFR the better option for the data we have.
Gregory, Thompson & Tifft 1981:
116 new galaxy redshift determinations, forming complete set of 141. Similar to other redshift surveys in that they're located in cllusters and superclusters, and large voids are seen. Results support that supercluster-mass clouds fragment before galaxies do and communicate these changes anisotropic (non-uniform based on direction) matter and velocity distributions to galaxies.
Survey covers 13 fields of Zwicky catalog. Establishes generally that 1) existence of respective superclusters, 2) galaxies located outside of superclusters are found in groups and clusters, not a smooth field, 3) large columns of space are devoid of (at least) highly luminous galaxies.
Haynes, Giovanelli 1986:
In the southern region of the Pisces-Perseus Supercluster, some narrow structures seem to connect it to the Local Supercluster. These filamentary connecting structures are pretty well understood, but it is still unknown how prominent they are in the universe. Recording redshifts for a number of spiral galaxies in the Pisces-Perseus Supercluster region via HI line observing gives more insight into the complexity of such structures, as well as how the Supercluster is connected to the Local Supercluster. The observations of sheets, voids, and connecting filaments in the PPS show that galaxies likely occupy specific volumes of the universe.
Giovanelli, Haynes, Chincarini 1986
The explanation for the distribution of matter in the PPS region may place constraints on relative formation of other large-scale structures like the PPS. As prior knowledge shows, ellipticals dominate cores of rich clusters, less populous in open space fields.
Morphological segregation must reflect the early environmental conditions during galaxy formation as they cannot really be explained by density-dependent evolution. This paper explores morphological type distribution in the PPS.
While the information given as of 1985 did not permit a complete analysis of morphological effects of volume density, PPS still provides information to study consequential tendencies of morphological segregation.
Main conclusions:
1) Surface density enhancements do match up with volume density enhancements in the supercluster. 2)Early type galaxies, as similar prior results have shown, rend to cluster on smaller angular scales than later type spirals and irregulars. 3) Population fractions of elliptical and lenticular galaxies in Perseus grows with increasing density while spirals grow with decreasing density. Overall spirals decrease as galaxy grows, however type Sa and Sab increase while Sbc and Sc decrease. (note: Sab seems to be the cutoff for necessary galaxy density to increase over galaxy growth time period)
Analysis suggests that the conditions of spirals that led to morphological segregation distribution arise in large part due to matter density at the time of formation or at lest in early stages of the galaxy formation.
If initial perturbations formed galaxies then clusters and superclusters by dissipationless collapse then morphological segregation uses environment dependent mechanisms which drastically alter galaxy evolution in a density-sensitive manner. If large-scale perturbations collapsed first, pregalactic material density may be the main cause of development. Oort pointed out necessary cloud size/mass in formation of a galaxy depends on density as does angular momentum, which does play a role in galaxy morphology.
Adiabatic: energy transferred only as work. More complete redshift database which would provide a true 3-D framework of galaxian distribution in the PPS.is necessary to improve the results of a study like this.
Giovenelli et al 2005:
ALFALFA (Arecibo Legacy Fast ALFA) survey maps 7074 deg^2 of Arecibo sky between 0 and +36 deg in declination, 07h30m-16h30m and 22h00m-3h00m in right ascension. Frequency coverage between 1335-1435 MHz. 20000! H1 sources expected to be detected. Started in 2005.
WAPP: Wideband Arecibo Pulsar Processor
\(\frac{M_{HI}}{M_{sun}}=2.356\ \cdot10^5D_{Mpc}^2\int_a^bS\left(V\right)dV\) where S(V) is the \(H_I\) line profile in Jy and V is Doppler velocity in km/s
Two-pass process would greatly reduce errors and missing parts of mapping that may occur due to many variables in data collection.
Arecibo telescope is most sensitive telescope in the L-band
Wegner, Haynes, Giovanelli, 1993:
544 radial velocity measurements, 229 optical and 315 HI presented. Pisces-Perseus is 5500 km/s~. Main ridge of the PPS ranges from 22h>RA>4h. Arecibo and the late 91m Green Bank telescope used for HI. At high zenith angles Arecibo suffers from vignetting and spillover which both cause a decrease in system sensitivity. Optical data was taken with the 2.4m Michigan-Dartmouth-MIT telescope and used absorption spectra from K-giant stars. Observing the overall "connective structure" is key. Large overdensity is seen in the ridge from 4500-6500 km/s, depth being 7-10 Mpc.
Conclusions:
Large overdensity at 5000 km/s with large underdensity in foreground. Typical redshift depths are from 250-500 km/s.