Newbie Seeks Red Shift data

I've been playing around with Red Shift calculations
and this is probably a simple question for anyone
experienced in the field, but I'm looking for
the best data that gives both the Z shift
and distance measured using a method other than
the hubble constant. In other words I'm looking
for the data that the Hubble constant is calculated
from. I'm only looking for light emitting objects
not quasars or radio sources.

I've looked in Google and a couple of beginning
astromomy books which had a couple of charts but
not the actual measurements. Also they seem to not
give any estimate as to which measurements are the
best or most accurate. If someone could please
point me to a textbook or the original papers containing
the best estimates of stellar or galactic distances
together with the corresponding red shift for those
objects it'd be a big help to me.

Thanks in advance.

bjacoby

--
SPAM-Guard! Remove .users (if present) to email me!

Dear bjacoby:
wrote in message
...
I've been playing around with Red Shift calculations
and this is probably a simple question for anyone
experienced in the field, but I'm looking for
the best data that gives both the Z shift
and distance measured using a method other than
the hubble constant. In other words I'm looking
for the data that the Hubble constant is calculated
from. I'm only looking for light emitting objects
not quasars or radio sources.

You might try this:
http://www.stellar-database.com/

And there may be stuff linked off the FAQ...

David A. Smith

\(formerly\)" dlzc1.cox@net wrote:

Thanks! And could you tell me how to access the FAQ for
this group?

----------------------------

You might try this:
http://www.stellar-database.com/

And there may be stuff linked off the FAQ...

David A. Smith

--
SPAM-Guard! Remove .users (if present) to email me!

... but I'm looking for
the best data that gives both the Z shift
and distance measured using a method other than
the hubble constant. In other words I'm looking
for the data that the Hubble constant is calculated
from. I'm only looking for light emitting objects
not quasars or radio sources.

You can find several references to papers which compare different
methods of distance measurement (other than redshift) at the bottom of
this lectu

http://spiff.rit.edu/classes/phys240...t/distant.html

Look for the papers by the HST Key Project Team.

These discuss only relatively nearby galaxies, which are so close
that their peculiar velocities are a good fraction of their recession
velocities. You'll have to do some searching to find good references
which deal with galaxies more distant than, say, the Coma cluster (of
course, there aren't any really good methods for measuring the
distance to such galaxies).

I suggest you go to the ADS search page:

http://adsabs.harvard.edu/abstract_service.html

and type words like "distance measurement galaxy methods" into the box
labelled "Abstract Words".

Good luck.

Michael Richmond

Dear
wrote in message
...
\(formerly\)" dlzc1.cox@net wrote:

Thanks! And could you tell me how to access the FAQ for
this group?

Dr. Lazio posts a Welcome message every week or so. From it, I find...

QUOTE
This post is an extract of the material found in the sci.astro FAQ.
The FAQ is posted on a regular basis to the newsgroup sci.astro. It
is available via anonymous ftp from
URL:ftp://rtfm.mit.edu/pub/usenet/news.answers/astronomy/faq/, and
it is on the World Wide Web at
URL:http://sciastro.astronomy.net/sci.astro.html and
URL:http://www.faqs.org/faqs/astronomy/faq/. A partial list of
worldwide mirrors (both ftp and Web) is maintained at
URL:http://sciastro.astronomy.net/mirrors.html. (As a general note,
many other FAQs are also available from
URL:ftp://rtfm.mit.edu/pub/usenet/news.answers/.)
END QUOTE

David A. Smith

wrote:
Thanks for the additional info. I already have found
http://www.astro.ucla.edu/~wright/distance.htm
Which seems to be a nice summary of the various
non-RS methods used to calculate distances.

While that was good, I'm at this point trying to
find the actual measurements on objects to obtain
data of distance vs z.

I'm sure this must be common stuff. I've uncovered a
few charts of the Hubble constant where they show
distance and z with the Hubble constant being a best
fit line to that data. But while I've seen the charts
so far I haven't found the actual numbers used to
make the chart. (I haven't made it over to
www.stellar-database.com yet)

As a start, the HST Key Project team published their final summary
in Astrophysical Journal 553, 47 (2001, Freedman et al.). Their
data are as follows:

Name DM error N v0
NGC 224 24.38 0.05 37 -62
NGC 300 26.53 0.07 14 241
NGC 598 24.56 0.10 11 6
NGC 925 29.80 0.04 72 709
NGC 1326A 31.00 0.09 15 1695
NGC 1365 31.20 0.05 47 1489
NGC 1425 31.54 0.05 20 1378
NGC 2090 30.27 0.04 30 702
NGC 2403 27.48 0.24 10 259
NGC 2541 30.26 0.07 29 601
NGC 3031 27.67 0.07 17 105
NGC 3198 30.64 0.08 36 689
NGC 3319 30.64 0.09 33 749
NGC 3351 29.90 0.10 48 644
NGC 3368 29.95 0.08 9 765
NGC 3621 29.06 0.06 59 463
NGC 3627 29.71 0.08 16 613
NGC 4258 29.44 0.07 15 520
NGC 4321 30.75 0.07 42 1504
NGC 4414 31.18 0.09 8 719
NGC 4496A 30.80 0.03 94 1618
NGC 4535 30.84 0.05 47 1868
NGC 4536 30.78 0.04 35 1691
NGC 4548 30.88 0.05 24 421
NGC 4639 31.59 0.07 14 944
NGC 4725 30.33 0.06 15 1199
NGC 5253 27.54 0.10 4 221
NGC 5457 29.18 0.10 25 288
NGC 7331 30.81 0.09 13 1095
IC 4182 28.26 0.05 16 375
IC 1613 24.24 0.14 9 -121

DM is the distance modulus, 5 log (D, pc/10)
N is the number of Cepheids used for distance determination in each galaxy
v0 is the redshift expressed as velocity, corrected for the solar
motion to the galactic center reference frame

Their strategy included distances to galaxies which have hosted well-
observed supernovae, for example, so there are many in Virgo for
which the internal motions introduce a large scatter. This shows
up well in a plot (I have one at
http://www.astr.ua.edu/keel/galaxies/distance.html)
where all the non-Virgo members trace a narrow relation, but the cluster
members fill an ellipse about 1200 km/s in extent. The galaxy in the
middle of the "Virgo" region is in fact NGC 7331 in almost the
opposite direction.


Bill Keel

go to google put in extragalactic articles
go to site

wrote:
From:
Subject: Newbie Seeks Red Shift data
Newsgroups: sci.astro
References:
Organization:

William C. Keel wrote:

I wrote:
(I haven't made it over to
www.stellar-database.com yet)

....snip...

And though I hate to be a pest (I warned you I was a newbie)
I don't quite understand your "distance modulus". What formula
would I use to get the galactic distance in light years?
And what formula would I use to get the red shift Z factor
out of the velocity? I've seen fairly simple ones to do
that but people talk about all kinds of corrections and things.

Oops, sorry, I am bad at reading the right level of response from
people's posts. DM is what Freedman et al. tabulated, and when I
do plots it gets turned into distance internally. By definition,
DM is the difference between apparent and absolute magnitudes for
something at distance D:
DM = 5 log (D/10) for D in parsecs.
So
10^(0.2 DM) = D/10 pc
and
D = 10^(1+.2 DM) in parsecs; multiply by 3.26 for light-years.

(It's early, but I think I did the inversion right).

The redshift values listed were corrected to the Milky Way mean
frame, as best we know it, so you can retrieve z quite accurately
as z=v/c for these small values.


Bill Keel