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Samreay / Marz

The Marz redshifting program is intended for use in cosmology surveys, specifically for the OzDES team.
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Redshifting spectra with a redder spectral coverage than the standard OzDES setting #148

Open clidman opened 6 years ago

clidman commented 6 years ago

I a currently using Marz to redshift Gemini data of a galaxy cluster at z=1.05, using spectra that have a spectral range going from 560 to 1040nm. Xcor seems to be done up to z=1.0 and no further. Is there a parameter one can set that ensures that the Xcor is done over a larger redshift range.

Note also that one gets starts from time to time, and some stars a blueshifted, so the lower bound should be -0.01. I suspect that it is at zero.

Samreay commented 6 years ago

Unfortunately there isn't at the moment. Changing the redshift range is not actually trivial either, as it would require recreating the log bins for all templates and additionally renormalizing the template weights. There is a fork of Marz which has high redshift templates, I'll look up who made the fork when I'm off the bus.

On 5 Dec. 2017 1:25 pm, "clidman" notifications@github.com wrote:

I a currently using Marz to redshift Gemini data of a galaxy cluster at z1.0, using spectra that have a spectral range going from 560 to 1040nm. Xcor seems to be done up to z1.0 and no further. Is there a parameter one can set that ensures that the Xcor is done over a larger redshift range.

Note also that one gets starts from time to time, and some stars a blueshifted, so the lower bound should be -0.01. I suspect that it is at zero.

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/Samreay/Marz/issues/148, or mute the thread https://github.com/notifications/unsubscribe-auth/AGb5WdDuPv44qeOfsV6tymm-BMWFlc7Yks5s9KmmgaJpZM4Q1oha .

clidman commented 6 years ago

Hi Sam, I know that you have an incredibly busy couple of weeks coming up, so you should not worry about this now.

OzDES is obtaining redshifts for objects up to z~1.36. This is where the [OII] line reaches the end of the spectral range. During a run with AAOmega in February next year, I’ll be using a setup that should enable us to get redshifts of objects up to z~1.6.

Hence there is an argument for extending the upper bound of where the cross correlation is done to z~1.3 and preferably z~1.6.

Cheers,

Chris.

Dr. Chris Lidman Head of National Facilities Support Australian Astronomical Observatory Phone: ++61 (0)2 9372 4823

On 5 Dec 2017, at 5:11 PM, Samuel Hinton notifications@github.com wrote:

Unfortunately there isn't at the moment. Changing the redshift range is not actually trivial either, as it would require recreating the log bins for all templates and additionally renormalizing the template weights. There is a fork of Marz which has high redshift templates, I'll look up who made the fork when I'm off the bus.

On 5 Dec. 2017 1:25 pm, "clidman" notifications@github.com wrote:

I a currently using Marz to redshift Gemini data of a galaxy cluster at z1.0, using spectra that have a spectral range going from 560 to 1040nm. Xcor seems to be done up to z1.0 and no further. Is there a parameter one can set that ensures that the Xcor is done over a larger redshift range.

Note also that one gets starts from time to time, and some stars a blueshifted, so the lower bound should be -0.01. I suspect that it is at zero.

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/Samreay/Marz/issues/148, or mute the thread https://github.com/notifications/unsubscribe-auth/AGb5WdDuPv44qeOfsV6tymm-BMWFlc7Yks5s9KmmgaJpZM4Q1oha .

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Samreay commented 6 years ago

Hmm, yeah, lets touch base about it after DES cosmology. Its definitely doable, just concerned over the flow on impacts regarding the autoQOP and the overarching concern of introducing a small redshift change when the behind the scenes algorithm changes at all.

On Wed, Dec 6, 2017 at 1:31 PM, clidman notifications@github.com wrote:

Hi Sam, I know that you have an incredibly busy couple of weeks coming up, so you should not worry about this now.

OzDES is obtaining redshifts for objects up to z~1.36. This is where the [OII] line reaches the end of the spectral range. During a run with AAOmega in February next year, I’ll be using a setup that should enable us to get redshifts of objects up to z~1.6.

Hence there is an argument for extending the upper bound of where the cross correlation is done to z~1.3 and preferably z~1.6.

Cheers,

Chris.

Dr. Chris Lidman Head of National Facilities Support Australian Astronomical Observatory Phone: ++61 (0)2 9372 4823 <+61%202%209372%204823>

On 5 Dec 2017, at 5:11 PM, Samuel Hinton notifications@github.com wrote:

Unfortunately there isn't at the moment. Changing the redshift range is not actually trivial either, as it would require recreating the log bins for all templates and additionally renormalizing the template weights. There is a fork of Marz which has high redshift templates, I'll look up who made the fork when I'm off the bus.

On 5 Dec. 2017 1:25 pm, "clidman" notifications@github.com wrote:

I a currently using Marz to redshift Gemini data of a galaxy cluster at z1.0, using spectra that have a spectral range going from 560 to 1040nm. Xcor seems to be done up to z1.0 and no further. Is there a parameter one can set that ensures that the Xcor is done over a larger redshift range.

Note also that one gets starts from time to time, and some stars a blueshifted, so the lower bound should be -0.01. I suspect that it is at zero.

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/Samreay/Marz/issues/148, or mute the thread https://github.com/notifications/unsubscribe- auth/AGb5WdDuPv44qeOfsV6tymm-BMWFlc7Yks5s9KmmgaJpZM4Q1oha .

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub < https://github.com/Samreay/Marz/issues/148#issuecomment-349206150>, or mute the thread https://github.com/notifications/unsubscribe- auth/APBohEAW6r8-z9kjuspbsgNo34m0js86ks5s9N56gaJpZM4Q1oha.

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