Tired light and supernovae

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by EBTX</i>
<br />What you seem to be saying here is that they did not actually have the whole enchilada in hand for all 60 cases but rather "inferred" missing parts by referring to "The Model"? And therefore, the "completed" data then fit that model retroactively? This would constitute a scientific breach if true.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">In many cases, they did not observe the maximum, but found the supernova some number of days after maximum. But their confidence was high that BB was basically correct, so they only needed to show consistency.

Technically, it would only be a breach if they were trying to distinguish two models. No physically realistic foil model was ever used for comparison in the analyses.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">The http for the graph is on my first entry to this thread (from Ned Wright's Cosmology site). "In 2001 Goldhaber and the Supernova Cosmology Project published results ..."<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Read section 3.2 in the Goldhaber paper, titled "templates". You will see that the "widths" in the plot are not simply measurements, but are fits to templates. The trick is in choosing which template to fit to. With BB assumptions, they did it right. With e.g. MM assumptions, they did it wrong.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">If there were (in principle) no intrinsic, standard, light curve in Type1As, then, the resulting graph should be simply meaningless, i.e. random.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">The standard lightcurve is the set of templates. The devil is in the details of choosing the right template, which depends on intrinsic brightness, which depends on the <i>assumed</i> redshift-distance relation.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">At what point does the Malmquist bias "kick in" for supernovas?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">At any distance where the sample is not complete.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Is there not a lower limit to the brightness of a supernova? And ... isn't that lower limit eminently visible to anyone looking in that direction with a proper instrument? What I am getting at ... is ... can there be unobservable supernovas at, say, less than z=.8 ?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Most supernovae at all distances go unobserved because no one is looking at the right time. The chances of a supernova being noticed increase greatly with its brightness. Nearby supernovae sample a relatively small volume of space and therefore are incomplete because of being too few in number, so that the intrinsically brightest events are usually not represented. -|Tom|-

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">At any distance where the sample is not complete.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
How many square degrees would a proper sample subtend? I assume that a Hubble deep field survey would cut a small angle and would "see" every supernova from, say, z=.4 to z=.8 without possibility of a miss over, say, a two year time period with a new picture taken every day.

Is this a realistic expectation for such a survey? If not, how could it fail to detect such a bright object?

Side issue:
Isn't the only way to "focus" the Hubble telescope on a particular distance ... by means of altering the angle subtended and/or the time of photographic exposure?

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by EBTX</i>
<br />I assume that a Hubble deep field survey would cut a small angle and would "see" every supernova from, say, z=.4 to z=.8 without possibility of a miss over, say, a two year time period with a new picture taken every day.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">The chances of getting even one supernova inside a given Hubble field are miniscule. There are still less than 100 observed over the whole sky (41,000 square degrees) in that redshift range since the program began. Sample incompleteness is still a major factor with supernova data. -|Tom|-

Tom or anyone who may know,

If you have two supernova: a and b.

Supernova a is travaling .3c
Supernova b is travaling .7c

Would the same process not occur at a faster rate on Supernova b than on Supernova a?

Thanks.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by rousejohnny</i>
<br />If you have two supernova: a and b. Supernova a is travaling .3c. Supernova b is travaling .7c. Would the same process not occur at a faster rate on Supernova b than on Supernova a?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">The process would occur at a faster rate on the slower supernova a. If redshift is caused by velocity, then the Big Bang interpretation is correct.

But there is plenty of evidence that redshift is not caused by velocity. -|Tom|-

Tom,

I should be more elaborative with my concerns, and I apoligize.
In the given example EBTX has provided data that suggest that for each tenth redshift increases that the with would increase exactly .1. I was try to elaborate that this would not be possible.

An observer is watching two balls of spinning clay. Spool A is spinning twice as fast a spool B. Would the process of the clay flattening from the spools not occur at a faster rate for spool A.

In order for the precision of EBTX's suggestion to be valid this could not be the case for these supernova. Their speed would have 0 effect on their "relative" metabolic rate. Unless the bandwidth also suggests something about the EBTX supported graph and its relativeness to some relationship between acceleration and metabolic rate that creates this 0 sum.