astronomers Huchra Da Costaredshift et al universe Shanks et al However rapid jected large visual Over available more recently from ob jective machine based scanning of the al rst discovery of acomplex cell like D structure structures rep orted b eeing by Jo eveer discovered et starting with the bution puter database to record alland published Meudon information was on formed galax in to establish the rst com empty region of galaxies the so called Bo otes void and H connected Received Sept accepted 3 2 1 Are astro-ph/9611211 26 Nov 1996 Mon Not R Astron So c School of Physics UniversityObservatoire of de New Lyon South F Wales Saint Genis Sydney Laval NSW FRANCE AUSTRALIA Anglo Australian Observatory Coonabarabran NSW AUSTRALIA Later Kirshner INTRODUCTION Before the compilation Anticipating their Di recent scale studies Lick catalogue Shane Wirtanen D a collab oration surveys has the Schmidt Nella use galaxy galaxy years mapp ed emerged as progress e g de Lapparent a the Perseus Pisces sky distributio n to ol an distribution large scale growth with W J increasingly survey b etween the Observatories to with redshift et al describ e the of these large industry plates Key words detected and makes thethat total no length connexion of exists b this etween PP chain of and PI more However than a southern Mp c extension of PP was Pisces region was found b etween thefrom southern the Pavo LEDA Indus database PI is wall and plotted the in northern hypergalactic Perseus co ordinates A signi cant empty at Siding Spring Australia Two interesting in the galaxy distribution at sample previous p o or sampling of the galaxies in this region Redshifts for a magnitude selected the ABSTRACT Couch based advent of found a very structures In the FLAIR detailed et al Geller the Collins PP chain This survey this on surveys of lo cal of of D either redshift surveys large redshift question pap er multi ob ject from picture G d galaxy et galaxies catalogue redshifts large scale structures led galaxies Printed May systematic sub jective al Paturel chain the or we to more of Lyon surveys of distri that Mp c large present pro and the were sp ectroscopy arises with a obtained and Q A ies equal typical ters voids laments the plane by Tully in sp ectively and This most is p opulated tilted plane by ab out MPP also ten degrees claimed to l p ole and the Lo cal Sup ercluster Theeral LEDA team calculated the Paturel et al even The larger structure than any seemedthe previously to LEDA seen connect database Bottinelli sev suggested et al the existence of a structure voids and this alignement via an equal area pro jection of galaxy p ositions lyon fr gion tests new when M pc deg Lyon Meudon highly signi cant density LEDA Using sup erclusters Huchra of this attened hypergalactic redshift Geller and l area the and deg login feature all the system Parker covering B of the Lo cal reality of this void which may simply re ect discovered the b pro jection the T Around this and deg in galactic longitude and latitude re leda survey CfA redshift scales M pc currently of sup erclusters Pavo Indus Extragalactic on b Huchra Perseus the deg Lynden Bell also noticed graphically All the H and of a of undertaken four Sup ercluster 0 lament km s sheets was b eing time the existence available redshift Mp c redshifts Pisces UKST SERC m survey De Database enhancements con rmed U K on the sup ergalactic galaxies showed in to In Pavo Indus structure to b e ab out de Vaucouleurs 1 the were Mp c Schmidt address that Lapparent telnet wall Coma then the obtained con rmed survey a Flamsteed s 1 of sup erclus this We claim information were existence available the Telescope cluster Centaurus lmc univ lament rather elds found Geller plane with with re in of
2 Di Nel la H et al
all p ossessing their own selection criteria biases and errors
Incompleteness in some of these surveys is also o ccurring just
where the walls are b ecoming p opulated Furthermore our
azimuthal view is incomplete due to the zones of avoidance
in the Milky Way and p ossible p o or sampling in certain
directions
Thus to ascertain whether the great walls seen are part
of yet larger shell like structures we have b egun a redshift
survey to map the galaxy distributio n out through and b e
yond the great walls We hop e to determine whether they
truly have an outer edge rather than b eing an artefact of
incomplete data and also to determine whether the appar
ent gaps b etween the walls are real or due to p o or sampling
Apart from b eing pierced by narrow p encil b eam surveys
the galaxy distribution b eyond the walls has so far b een
relatively p o orly studied
In this rst pap er we present results of a new redshift
survey in the direction b etween the Pavo Indus and Perseus
Pisces walls This is of particular interest b ecause of the ap
parent de ciency of galaxies in this direction seen in Figure
A prime motivator for studying this region rst was to see
if there is a p ossible link b etween these two ma jor walls as
suggested by D pro jections Paturel et al Santiago
et al
The pap er is organised as follows in section we de
Figure Distribution of galaxies from the LEDA sample in a
scrib e the selection of the galaxies to b e observed the ob
face on view of the so called hypergalactic plane see text The
serving pro cedure and the data reduction Section presents
newly observed region is de ned by the two continuous lines
the nal redshift results whilst the signi cance of our nd
ings are discussed in section
was actually a sheet like structure that has b ecome known
as the Great Wal l similar to structures predicted in mo dels
by Zeldovich In the southern hemisphere comple
OBSERVATIONS
mentary redshift surveys were undertaken by da Costa et al
and Fairall et al A compilation of available
Construction of the sample
published Southern redshifts by Fairall and Jones
revealed another wall like structure in the Pavo Indus PI
To obtain our sample we want to selected galaxies in the
empty region b etween Perseus Pisces and Pavo Indus This region The Perseus Pisces PP region was describ ed either
region corresp onds to the range deg hg l deg as a chain Jo ever et al Gregory Thompson and Ti t
or a sheet like structure Haynes and Giovanelli
and deg hg b deg in hypergalactic longitude
and latitude resp ectively We decided to limit ourselves in In the years since the inception of LEDA data for
hypergalactic latitude and study only the galaxies lying close some galaxies and more than redshifts have
to the hypergalactic plane This would encompass FLAIR b een collected From LEDA a volume limited v
1
observations across UKST SERC survey elds centered km s and diameter limited logD all sky sample
25
at approximately hgb deg see Table of galaxies was extracted After studying its complete
From the LEDA database which contains published ness in apparent diameter we used this sample to show that
the most p opulated plane in the lo cal Universe actually coin
data on known galaxies we selected all galaxies which are
p ositioned in one of the four UKST elds to b e observed cides with the hypergalactic plane or structure previously
Though entries on more than galaxies are currently found with the Flamsteed D pro jection Di Nella and Pa
turel and If real this would represent p ossibly
available from LEDA signi cant incompleteness exists for a
whole range of LEDA galaxy parameters includin g redshift the largest coherent structure in the Universe
magnitude and apparent diameters Sp ecially for galaxies This plane hereafter the hypergalactic plane is de
fainter than B magnitude LEDA b ecomes progressively ned by its up dated p ole and origin in galactic co ordi
incomplete nates l pol e deg b pol e deg and l or ig in
Thus it is necessary to complete the LEDA sample l pol e b or ig in b pol e deg To understand the sig
from a deep er catalogue We used the COSMOS database ni cance of this most p opulated plane we calculated that
currently on line at the AAO Drinkwater Barnes and at deg around this plane of the sample lay in only
Ellison The COSMOS database consists of param of the solid angle The distribution of the galaxies of
eterised image information for all ob jects detected ab ove the sample is shown in Fig
a given isophotal threshold from COSMOS measuring ma Despite the wealth of information in Figure there was
chine scans of the UKST SERC J survey plates of the whole still a clear need to improve the picture further via additional
of the Southern sky excluding the Milky Way Star galaxy redshifts Like the Fairall redshift compilation the available
separation is provided up to the limiting magnitude for LEDA redshifts are a collation from a wide variety of sources
Are the Perseus Pisces chain and the Pavo Indus wal l connected 3
upp er limit of seconds exp osure was adopted The typ
Table Details of the observations
ical total exp osure time p er eld was in the range s
to s s are normally considered adequate to
ESO SERC Set of Night of Seeing Total exp osure
obtain sp ectra of S N ratio eld galaxies Sept arcsec time sec
a th th
The G B grating was used giving A mm or
a th th
A pixel CCD resolution The A covered on the CCD
a th th
at this disp ersion was selected for the range A A
a th th
This choice provided
a th th
i su cient sp ectral coverage to give a go o d chance of see
b th th
ing a number of di erent absorption or emission features in
b th th
galaxies at di erent redshifts
ii a high enough disp ersion to get reasonable redshift accu
racy
galaxies of B though sources can b e detected up to
T
iii a minimum spreading of the galaxy light to get an ac
B Howeveer we only selected galaxies in the range
T
ceptable S N ratio
B This limit su ciently deep to provide
T
The current FLAIR system has very p o or e ciency b e
go o d sampling at the depths of interest is a go o d match to
low A but this problem has recently b een addressed by
the capabiliti es of FLAIR and provides a target list that can
the commissioning of a new back illumina ted thinned CCD
b e observed in reasonable timescales
which o ers times the blue DQE of the previous CCD
Some galaxies fainter than B can b e present in
T
To wavelength calibrate the data arc exp osures were
b oth LEDA and COSMOS subsamples see section Af
taken either side of a set of eld exp osures at the given dis
ter matching galaxies in b oth subsamples and rejectig galax
p ersion and grating angle The extremely stable nature of
ies with known redshift we obtained a total of galaxies
the o or mounted FLAIR sp ectrograph obviates the need
for redshift determination as shown in Table Five nights
for more frequent calibration exp osures e g Parker Wat
of FLAIR observing time were allo cated for the pro ject in
son Light from a selection of arc lamps is simply re
September Even with the bre multiplex advantage
ected o the closed dome Arc exp osures were also taken
and the capabili ty to observe ob jects a night by us
when we changed plateholders to account for the di erent
ing two FLAIR plateholders it was not p ossible to observe
bre formats fo cus values etc Both Neon and Hg Cd arcs
the total sample of selected galaxies in the nights available
were combined to provide adequate line coverage over the
Hence sets of galaxies p er UKST eld were randomly
observed wavelength range
selected at the rate of in as this gives a go o d match to the
Flat eld exp osures were taken using either the zenith
available bres in each FLAIR plateholder A nal sample
twilight sky or by re ection of a featureless quartz halogen
of galaxies was obtained
lamp o a sp ecially provided dome at eld screen These
exp osures are used to obtain the bre to bre transmission
function see Parker and Watson vital to ensure prop er
Observing pro cedure
sky subtraction Di erences b etween bre transmission e
ciencies b etween the twilight sky and dome ats are at the
The survey was undertaken using FLAIR the multi bre
level Parker Lee Bias frames were also
sp ectroscopy system on the m UK Schmidt telescop e at
taken b efore and or after observations in order to correct
Siding Spring Co onabarabran Australia FLAIR is ideal for
for any sensitivity variations cosmetic defects and system
this survey as it combines b oth a large eld of view deg
atic pixel to pixel variations on the CCD Of the or
deg a large multiplex advantage ob jects simulta
available bres dep ending on which FLAIR plateholder is
neously dep ending on the FLAIR plateholder used and a
used were devoted to the night sky to facilitate satis
su ciently faint limiting magnitude B to e ciently
T
factory sky subtraction across the wide eld
sample the volume of interest
The observations spread over ve nights from the th
to the th September are detailed in Table Unfor
Data reduction
tunately the rst night was lost due to p o or weather The
All the data reduction was p erformed using the NOAO second night was only partly clear with typical seeing of
IRAF sp ectral reduction package together with a few ad arcseconds The following nights were mostly go o d with see
ditional FLAIR sp eci c IRAF tasks A FLAIR IRAF data ing in the range arcseconds Two sets of galaxies
reduction manual exists to facilitate the pro cess Drinkwa p er eld were prepared with the idea of observing two sets
ter and Barnes It is based mainly on existing IRAF of galaxies p er night by swapping b etween the two available
packages for multi ber sp ectroscopy such as dohydra The plateholders This was accomplished on three nights but due
nal derivation of the radial velocities was done using the to weather conditions and some equipment problems half
rvsao cross correlation IRAF package night exp osures were sometimes not enough to obtain data
The rst stage of the pro cess is to combine several bias of adequate S N In these cases plateholder changeover was
exp osures into a single image this is required to remove any delayed to later in the night or to the following night
structure in the bias level across the CCD It is also nec The length of a FLAIR exp osure is determined mainly
essary to combine the at eld frames used to determine by the cosmic ray event rate typically p er minute Af
and correct for the relative transmission e ciency of the ter seconds cosmic ray events may b e detected
di erent bre ap ertures This frame is also used to de ne resulting in signi cant clutter of a data frame Imp ortant
and identify the bre ap ertures themselves The next stage features in galaxy sp ectra may thus b e compromised An
4 Di Nel la H et al
Table Selection of the target galaxies
HGB range HGL range RA and DEC UKST SERC number of number of
in deg in deg of eld centre eld number target ob jects observed ob jects
h deg
h deg
h deg
h deg
is to use the IRAF task ccdpro c This task removes the
electronic zero level rst by subtracting the combined bias
image from each frame and secondly by subtracting the av
erage over the columns in the overscan region Finally the
image is trimmed to leave just the part containing useful
data The individu al data frames are now combined to in
crease the S N ratio of the nal sp ectra At this stage the
cosmic ray events on each frame are e ectively removed us
ing a suitable sigma clipping algorithm which rejects pixel
whose values deviate signi cantly from the mean with min
imal loss of data An ap erture identi cation le is then cre
ated to sp ecify which ap ertures are sky and which contain
the ob jects The FLAIR data are now ready for nal pro
cessing using the IRAF dohydra task This complex task
was developed for the HYDRA multi bre system on the
KPNO m telescop e but can also b e e ectively used with
Figure Typical reduced absorption line galaxy sp ectrum not
FLAIR data From the combined cleaned and trimmed tar
ux calibrated with S N ratio The vertical axis average
get frames together with the dome ats and arc exp osures
counts p er exp osure e edu The apparent magnitude is
fully reduced disp ersion corrected wavelength calibrated
B The combined exp osure was s and V
T helio
sky subtracted one dimensional sp ectra were pro duced
1
k m s
Derivation of radial velocities
The reduced sp ectra from dohydra can then b e input to the
IRAF rvsao task to derive the galaxy radial velocities via
cross correlation against ltered templates provided by Q A
Parker Such reduction pro cedures are describ ed in detail by
Parker and Watson and Watson et al
We nally observed sets of galaxies elds
and were observed twice but lo oking at di erent galax
ies Among the galaxies observed gave reliable ra
dial velocities according to a set of strict criteria ccf p eak
height cut o and match b etween emission and absorption
line velocities An overall success rate of was achieved
Two fully reduced typical sp ectra are shown in Figure
and Figure for an absorption and emission line sp ectrum
resp ectively During the survey a signi cant number of ac
Figure Typical reduced emission line galaxy sp ectrum not
tive galaxies were also identi ed they will b e rep orted in a
ux calibrated with H H and S I I lines The S N ratio is
companion pap er
The vertical axis is average counts p er exp osure The apparent
The list of the measured galaxies is given in Table
magnitude is B The combined exp osure is s and
T
1
together with COSMOS co ordinates and apparent magni
V k m s
helio
tude These parameters plus diameter axis ratio and p o
sition angle were used to p erform cross identi cation with
the PGC LEDA ob jects after reduction to the RC system column Right ascension in hours minutes seconds
de Vaucouleurs et al Both cross correlation results
tenths for Equinox
from rvsao and emission line results from emsao are
column Declination in degrees arcminutes and arc
presented A few galaxies with published redshifts were also seconds for Equinox Co ordinates are from the COS
observed to derive our external error see section
MOS database except for a few cases were p ositions were
taken from the LEDA database
The columns of Table are arranged as follows column Internal eld number
Are the Perseus Pisces chain and the Pavo Indus wal l connected 5
Figure Comparison of new and published helio centric veloci
Figure Comparison of galaxy B magnitudes see text
ties see text
column PGC LEDA number Paturel et al a
b
due to p o or sampling of this region by previous surveys
column Alternative name in a given hierarchy ac
and therefore if there is a link b etween the Perseus Pisces
cording to LEDA database NGC IC ESO MCG FAIR and
and Pavo Indus Sup erclusters
DRCG Dreyer Laub erts Vorontsov
due to a real void of galaxies
Velyaminov et al Fairall and Dressler
due to an apparent void of galaxies caused by high
latitude galactic absorption
column B magnitude from COSMOS database af
T
ter reduction to the LEDA magnitude system Figure
To address these questions we rst present the new re
B B
T COSMOS
sults of this survey in Figure It is imp ortant to under
column Helio centric velocity V from the cross
cc
stand that the plane of this cone diagram is exactly the
1
correlation metho d and its mean error in k m s
same as the plane of Figure the hypergalactic or most
column Helio centric velocity V from the emission
em
p opulated plane There is evidence of two density enhance
1
lines identi cation metho d and its mean error in k m s
ments at a radial distance of and Mp c Their
column notes
signi cance seem more clear with the help of a redshift his
togram shown in Figure It app ears in Figure that these
enhancements delineate two low density regions or voids
Radial velocity external error estimates
When compared to the maps of this region given in the
compilation of Fairall Jones these voids are real
To determine the external mean error we made a comparison
1
and signi cant The nearest one with v km s is
Fig b etween our new measured velocities and those avail
known as the Sculptor Void and the furthest with v
able in LEDA for the few ob jects in common This compari
1
km s was called the Further Sculptor Void by Fairall
son con rms that there is no signi cant error for the slop e or
Jones This gure is very interesting b ecause it represents
for the zero p oint Rejecting two uncertain measurements
1
one of the rare regions where two walls p erp endicul ar to the
the residual error is km s If we assume that b oth
line of sight are seen We call these chains seen from our
LEDA and the measurements of this survey have the same
1
survey walls b ecause they are part of structures which ex
mean error we get a mean error of V km s
cc
tend ab ove and under the plane of this cone diagram see
The helio centric velocities measured by the emission
Fairall s catalogue of maps of this region
line detection metho d are also compared to published values
When we add these new redshifts to the data of Figure
despite there b eing only p oints in common No slop e or
no evidence of a link b etween the northern Perseus Pisces
zero p oint error is found This is con rmed by a compari
and the southern Pavo Indus features can b e seen The cur
son with radial velocities obtained by the cross correlation
1
rent survey sampled at a rate of in is highly signi cant
metho d The mean error is tentatively k m s
and thus we conclude that we cannot have missed any link
if one existed
The most prominent feature in Figure is the double
RESULTS
p eaked velocity distribution The rst p eak at V
hel
1
km s seems to result from galaxies lo cated in a southern The aim of this survey was to study the distributio n of galax
extension of the Perseus Pisces wall which now extends over ies in the region b etween Perseus Pisces and Pavo Indus see
more than Mp c The second p eak is lo cated at V gure With this study we hop ed to ascertain whether the
hel
1
km s apparent gap b etween these two walls seen in Figure is
6 Di Nel la H et al
standard parameters M and The func
tion is normalized to our sample total of galaxies
Assuming Poisson errors b oth p eaks are signi cant at a
level of and resp ectively It is also clear that the re
gions corresp onding to the Sculptor and the Further Sculp
tor voids are not consistent with a uniform average space
density of galaxies but really are under p opulated regions
DISCUSSION AND CONCLUSIONS
One could argue that the observed galaxy distribution is the
result of selection e ects Indeed if our sample was chosen in
a biased way e g with more time devoted to a given region
at a given distance one could susp ect that the p eaks sim
ply re ect the excess of time sp ent at this distance Several
arguments can b e presented against this interpretation
Our selection was made on the basis of carefully con
trolled criteria B and without regard to the
T
lo cal density or to distance Thus the observed density at a
given distance should b e representative In interpreting fea
tures of the redshift distribution in this way one must b e
extremely worry ab out the selection e ects which bias our
Figure Distribution of galaxies within the region surveyed in
this study The lled circles represent LEDA galaxies previously
view of the structure that is present For example could the
measured in redshift the op en circles are from this survey This
p eaks observed in the velocity distribution simply indicate
is a view face on of the hypergalactic plane plane with the Pavo
that our sample is preferentially tuned to galaxies at these
Indus wall and Perseus Pisces chain The p osition of the density
distances From the selection function we have computed
p eaks seen in the velocity histogram are indicated by the cir
the answer in our case is no
cle arcs One of this velocity p eak in the redshift survey shows
A completeness test can b e made to prove that our
a southern extension to Perseus Pisces which now extends over
sample constitutes a magnitude limited sample with a well
more than Mp c
de ned limit Figure This diagram has the exp ected
slop e of indicatin g that the number of studied galax
ies increases on the mean as the cub e of the distance For
comparison we plotted on the same gure the completeness
curve for the entire sky normalised to the solid angle of the
present survey obtained from LEDA when imp osing that
b oth the apparent magnitude B and the radial velocity v
T
are known The completeness limit in the studied region is
magnitude deep er after our survey
Another argument comes from the diagram Figure
which shows that the density enhancements are visible in
each covered eld at the same distance
Finally the nearest of the two walls was already visible
in the cone diagrams compiled by Fairall and Jones
This wall delineates the Sculptor void and the Further Sculp
tor void It is p erp endicul ar to the Sculptor Wall The fur
1
thest wall at km s has never b een noticed b efore
It delineates the end of the Further Sculptor Void and is
p erp endicul ar to the Scuptor Wall
Figure Histogram of helio centric velocities in the studied re
To continue to address the questions exhibited in sec
gion The dashed line represents the selection function of our sur
tion we have explored the map of Burstein Heiles
vey The most imp ortant features are the two highly signi cant
to see if a high galactic latitude molecular cloud could b e
p eaks bracketting under p opulated regions
resp onsible for an apparent void in the distributio n of galax
ies such as the Sculptor Void If this was the case the p os
sibility of a hidden connection b etween Perseus Pisces and
Pavo indus could still exist However we have already a hint They are compared to the calculated selection function
Fairall Jones didn t see a second wall delimitin g the end of our survey derived from a standard non evolving galaxy
of the Further Sculptor void but we did So it would b e luminosity function Because we are claiming that our sam
very surprising if the galactic absorption could play a role ple is complete b etween B and B we cal
T T
dep ending on distance i e hiding some near galaxies and not culated the selection function b etween these limits using
some more distant ones Reinforcing this answer no mapp ed a Schechter function Schechter and Press with the
Are the Perseus Pisces chain and the Pavo Indus wal l connected 7
Dynamique des Structures Gravitationnelles Observatoire de
Lyon
Burstein and Heiles ApJ Suppl
Da Costa L N Pellegrini P S Sargent W L W Tonry J Davis
M Meiksin A Latham D W Menziers J W Coulson I A
ApJ
Di Nella H and Paturel G Comptes rendus de l acad emiedes
sciences s erieI I t p
Di Nella H and Paturel G Pro ceedings of the Astronomical So
ciety of Australia vol
Dressler A Astrophys J Suppl Ser
Dreyer J L E MNRAS NGC
Dreyer J L E MNRAS IC
Drinkwater M J Barnes D G Ellison S L Publ Astron
So c Aust
Einasto J Corwin H G Huchra J Miller R H Tarenghi M
Highlights of Astronomy Vol ed R West Reidel
Dordrecht p
Einasto M Einasto J Tago E Dalton G B and Andernach
H Mon Not R astr Soc EETDA
Fairall A MNRAS FAIR
Figure Test to show that our sample constitutes a magnitude
Fairall A Jones A Southern Redshifts Catalogue Plots
limited sample with a well de ned cut o at B The solid
Publications of the Department of Astro
T
line represents the exp ected slop e The mean completeness
Fairall A P Palumbo G G C Vettolani G Kau mann G Jones
curve obtainied from LEDA for the same solid angle is shown in
A Baiesi Pillastrini G MNRAS P
op en circles A gain of magnitude results from our survey
Geller M Huchra J Science
Gregory S A Thompson L A Ti t W ApJ
Haynes M P Giovanelli R ApJ L
absorbing cloud is present in the available absorption maps
Jo eveer M Einasto J Tago E MNRAS
Kirshner R P Oemler A Schechter P L Shectman S A
in this direction
ApJ Lett L
In conclusion we no longer susp ect a link b etween the
Lapparent V de Geller M Huchra J ApJ L
Perseus Pisces and Pavo Indus walls despite evidences from
Laub erts A The ESO Uppsala Survey of the ESO B At
D pro jections Paturel et al Santiago et al
las Europ ean Southern Observatory ESO
Nevertheless Figure is still a very go o d representation of
Lynden Bell D in Clusters and Sup erclusters Ed A C
our neighbourho o d Up dating this gure will b e done only
Fabian p
by studying the outer regions of the ma jor walls and trying
Parker Q A Lee D AAO do cument on FLAIR p erfor
to ll in the missing data across the zones of avoidance The
mance
Further Sculptor Void can now b e considered delimited by
Parker Q A Watson F G A A Suppl
1
a wall at km s and Perseus Pisces is extended in
Parker Q A Watson F G SPIE vol
Paturel G Bottinelli L Gouguenheim L Fouqu eP A A
the Southern hemisphere The total length of this chain is
now more than Mp c
Santiago B X Strauss M A Lahav O Davis M Dressler A
Huchra J P ApJ
Shane C D Wirtanen C A Pub Lick Obs
ACKNOWLEDGEMENTS
Schechter P Press W ApJ
Tully R B ApJ
We are grateful to those who have managed the LEDA
Tully R B ApJ
extragalactic database over the last years N Durand
Vaucouleurs G de Astronomical Journal
P Fouqu e A M Garcia R Garnier M Loulergue M C
Vaucouleurs G de Vistas Astr
Marthinet and C Petit We are also grateful to those who
Vaucouleurs G de Vaucouleurs A de Corwin H G Jr Buta
assisted during the observations the UKST sta S Besier
R J Paturel G Fouqu e P Third Reference Cata
logue of Bright Galaxies Springer Verlag RC
and K Sealey We acknowledge the COSMOS UKST South
Vettolani G In Astronomy from Wide Field Imaging edt
ern Sky Catalogue supplied by the COSMOS group at the
MacGillivray H T in press
Royal Observatory Edinburgh to the Anglo Australian Ob
Vettolani G Studying the Universe with Clusters of Galaxies
servatory This work has b een supp orted by grants from the
eds B ohringer H and Schindler S MPE Rep ort
Conseil R egional Rhone Alp es F and by the Institut Na
tional des Sciences de l Univers F We thank the University
Vorontsov Velyaminov B A Arkip ova V P Kranogorskaja A A
of New South Wales for welcoming us and for providing us
Morphological Catalogue of Galaxies Trudy
the facilities with which we have conducted this study Q A
Sternberg Stat Astr Inst
Parker is on sp ecial leave from the ROE to work at the AAO
Watson F G Oates A P Shanks T Hale Sutton D MN
We thank the referee for his comments
RAS
Zeldovich Y B A A
REFERENCES
Bottinelli L Gouguenheim L Fouqu eP Paturel G in La
8 Di Nel la H et al
Table The measured galaxies
RA DEC field PGC LEDA Alternat BT Vcc Err Vem Err Notes
h m s d number number name km s km s km s km s
a abs
a PGC ESO abs
b emi
b emi
b abs
a emi
a emi
b PGC ESO emi Sb
a emi
b abs
a emi
a abs emi
b PGC ESO abs SO
a abs emi
a abs
b PGC ESO emi Scd
b PGC ESO emi Sb
a emi
b LEDA abs
b emi
b abs emi
a PGC ESO abs
a emi
b PGC ESO A abs
a abs emi
b abs
a abs emi
b emi
b abs emi
b emi
b abs
a emi
b emi
b abs
b emi
b emi
b emi
b PGC ESO emi
a abs
b emi
b emi
b abs
b emi
b emi
a abs
a abs
a emi
b abs
a abs
b emi
a emi
b emi
a PGC ESO abs SO
a PGC ESO abs emi
a abs
Are the Perseus Pisces chain and the Pavo Indus wal l connected 9
Table continued
RA DEC field PGC LEDA Alternat BT Vcc Err Vem Err Notes
h m s d number number name km s km s km s km s
b PGC ESO abs E
b emi
b abs
a abs
a abs emi
a emi
b PGC ESO emi Sa
b emi
b emi
a abs
b emi
b emi
b abs
a abs
a emi
b emi
a abs
b abs
b PGC ESO emi Irr
a abs
b emi
b abs
b emi
a abs
a emi
a emi
b PGC NGC absE So
a abs
a emi
a PGC ESO emi
b PGC ESO abs
b abs
b LEDA emi
a emi
b abs
a abs emi
a emi
a abs
a LEDA emi
b PGC IC B abs
a emi
b emi
a abs emi
a emi
a emi
b PGC ESO emi
a PGC ESO emi
b PGC ESO emi
a abs emi
a abs
b abs
b PGC ESO emi
a abs
b emi
a emi
10 Di Nel la H et al
Table continued
RA DEC field PGC LEDA Alternat BT Vcc Err Vem Err Notes
h m s d number number name km s km s km s km s
a abs
b emi
a emi
a abs emi
a emi
b emi
a abs
b emi
b abs
b abs
b PGC ESO emi
a emi
a emi
a LEDA emi
a abs
a PGC ESO emi
b emi
b emi
a abs
a emi
b PGC ESO abs
a abs emi
b PGC ESO emi
a PGC ESO emi
a emi
a PGC FAIR abs
b PGC ESO A abs emi
a emi
b abs
b emi
a emi
b abs
a abs
a emi
b abs
a emi
a emi
a PGC FAIR abs emi
b abs
b PGC ESO emi
a emi
a PGC ESO emi
b emi
b PGC ESO emi
a abs
b PGC ESO abs
a abs emi
a abs
a abs
b emi
b emi
b emi
a abs
b emi
a abs
Are the Perseus Pisces chain and the Pavo Indus wal l connected 11
Table continued
RA DEC field PGC LEDA Alternat BT Vcc Err Vem Err Notes
h m s d number number name km s km s km s km s
b emi
a PGC ESO emi
a emi
b abs
a abs
b emi
a emi
b abs
b emi
a abs
a abs
a emi
b emi
a emi
a emi
a emi
a emi
a emi
a emi
a abs
a emi
a emi
a emi
a LEDA emi
a emi
a emi
a emi
a emi
a emi
a emi
a abs
a emi
a abs
a emi
a emi
a emi
a emi
a emi
a emi
a PGC NGC abs
a emi
a abs
a abs
a emi
a emi
a LEDA emi
a LEDA abs
a emi
a abs
a abs emi
a emi
a emi
a emi
a abs
a PGC ESO abs
12 Di Nel la H et al
Table continued
RA DEC field PGC LEDA Alternat BT Vcc Err Vem Err Notes
h m s d number number name km s km s km s km s
a abs
a emi
a emi
a PGC IC emi
a emi
a PGC ESO emi
a emi
a PGC ESO emi
a emi
a emi
a emi
a emi
a emi
a abs
a emi
a emi
a abs
a abs
a PGC MCG abs
a abs
a emi
a emi
a emi
a emi
a emi
a abs
a PGC abs
a PGC ESO emi
a emi
a emi
a emi
a emi
a emi
a abs
a emi
a emi
a emi
a emi
a LEDA emi
a abs
a emi
a abs
a PGC ESO abs
a emi
a emi
a PGC ESO abs
a PGC ESO emi
a abs
a abs
a abs
a emi
a PGC ESO emi
a PGC ESO abs emi
a abs
Are the Perseus Pisces chain and the Pavo Indus wal l connected 13
Table continued
RA DEC field PGC LEDA Alternat BT Vcc Err Vem Err Notes
h m s d number number name km s km s km s km s
a PGC ESO emi
a LEDA emi
a abs
a emi
a emi
a abs
a LEDA emi
a emi
a abs
a LEDA DRCG abs
a emi
a abs
a LEDA DRCG emi
a abs
a LEDA DRCG abs
a PGC NGC abs
a emi
a PGC ESO emi
a LEDA DRCG emi
a abs
a PGC ESO abs
a abs
a emi
a PGC ESO emi
a PGC ESO emi
a abs
a abs
a emi
a abs
a emi
a emi
a PGC ESO abs
a emi
a PGC ESO emi
a PGC ESO emi
a PGC ESO emi
a emi
a emi
a emi
a emi
a PGC ESO emi
a PGC MCG abs
a abs
a abs
a abs
a abs
a emi
a emi
a emi
a abs
a emi
a abs
a abs emi
a emi
14 Di Nel la H et al
Table continued
RA DEC field PGC LEDA Alternat BT Vcc Err Vem Err Notes
h m s d number number name km s km s km s km s
b abs
b abs
b abs
a abs
a abs
a PGC ESO emi
a abs
a abs
a abs
a abs
b LEDA abs
b emi
b emi
b emi
a abs
a abs
b emi
b emi
b abs
b abs
b abs
b abs
b abs
b abs
b abs
b abs
b LEDA abs
a LEDA abs
a abs
a abs emi
a LEDA abs
a abs
a abs
a abs
a LEDA emi
a abs emi
a abs
a LEDA abs
a abs
a abs
b emi
b abs
b abs
b abs
b LEDA abs
b abs
b abs
b abs
a abs
Note the in the notes column indicates a poor determination of the redshift
abs denotes redshift measured from absorption lines emi denotes redshift measured from emission lines