Author Topic: Peas Project  (Read 130001 times)

EigenState

  • Guest
Re: Peas Project
« Reply #60 on: July 12, 2008, 02:13:53 pm »
Greetings Kevin,

Quote from: ZookeeperKevin
Hi Eigenstate,

A very simple but powerful probe that we can use are line ratio diagnostic diagrams or BPT diagrams (named after Baldwin, Philipps and Terlevich). The different atomic species depend differently on physical properties such as density, abundance and source of ionisation, so by plotting the ratios of different lines and comparing to both empirical databases and theoretical models, we can tell something about what is occurring in the peas.

Right!  By the way, the basic assumptions that enter into that kind of analysis are discussed in Introduction to Spectral Line Profiles

Congratulations on your appointment at Yale.  New Haven can be nice enough once you get used to it.  :D

Best regards,
EigenState

Edit: 

The assertion that I had discussed the basic assumptions underlying BPT type analyses was substantively incorrect.  I had briefly discussed the conditions of effective thermal equilibrium that account for the relative spectral line intensities of transitions arising from different energy levels of the identical species.

By comparison, BPT analyses compare the relative spectral line intensities arising from different species.  The original paper by Baldwin, Philipps, and Terlevich is Classification parameters for the emission-line spectra of extragalactic objects.  That is a direct link to a PDF file of the original paper (Astronomical Society of the Pacific, Publications, vol. 93, Feb.-Mar. 1981, p. 5-19).
« Last Edit: July 12, 2008, 05:57:59 pm by EigenState »

zookeeperKevin

  • Galaxy Zoo Keeper
  • Admin
  • Hero Member
  • *****
  • Posts: 2020
    • View Profile
Re: Peas Project
« Reply #61 on: July 12, 2008, 06:24:56 pm »
The assertion that I had discussed the basic assumptions underlying BPT type analyses was substantively incorrect.  I had briefly discussed the conditions of effective thermal equilibrium that account for the relative spectral line intensities of transitions arising from different energy levels of the identical species.

By comparison, BPT analyses compare the relative spectral line intensities arising from different species.  The original paper by Baldwin, Philipps, and Terlevich is Classification parameters for the emission-line spectra of extragalactic objects.  That is a direct link to a PDF file of the original paper (Astronomical Society of the Pacific, Publications, vol. 93, Feb.-Mar. 1981, p. 5-19).


Hi Eigenstate,

I know the paper very well, plus the literature since then. We'll be measuring a number of emission lines from the spectrum.

EigenState

  • Guest
Re: Peas Project
« Reply #62 on: July 12, 2008, 06:49:21 pm »
Greetings Kevin,

I was totally confident that you do know the BPT paper.  I thought it might be of interest to the others following this effort.  I cannot help but believe that it is important that participants have the opportunity to understand the underlying principles.

Best regards,
EigenState

Rick Nowell

  • Hero Member
  • *****
  • Posts: 1333
  • Bristol, U.K.
    • View Profile
Re: Peas Project
« Reply #63 on: July 12, 2008, 06:57:47 pm »
I was totally confident that you do know the BPT paper. 
Absolutely so; I also was sure Zookeeper Kevin would know this paper well.

laihro

  • OotD posters
  • Sr. Member
  • ****
  • Posts: 463
    • View Profile
Re: Peas Project
« Reply #64 on: July 13, 2008, 07:44:00 am »
Hello folks,

I have given a list of finally 2157 object ids to waveney and he told me that it is no big deal to suit the merger hunter tool for pea hunting. The candidate list also contains 173 of 197 objects that we have already identified. I have done this to create a consensus of what's green and to create some feeling of success for the users.
The redshift range of the list is 0.149<z<0.4. I still don't see why I should look at objects in the range 0.4<z<0.45 if they can't be green.

Now join in for a "Hurray on Waveney". (I hope that rhymes in english  :D)
« Last Edit: July 13, 2008, 07:47:27 am by laihro »
IMHO. And I don't have a clue ...

Alice

  • Global Moderator
  • Hero Member
  • ****
  • Posts: 31782
    • View Profile
Re: Peas Project
« Reply #65 on: July 13, 2008, 09:36:27 am »
Hello folks,

I have given a list of finally 2157 object ids to waveney and he told me that it is no big deal to suit the merger hunter tool for pea hunting. The candidate list also contains 173 of 197 objects that we have already identified. I have done this to create a consensus of what's green and to create some feeling of success for the users.
The redshift range of the list is 0.149<z<0.4. I still don't see why I should look at objects in the range 0.4<z<0.45 if they can't be green.

Now join in for a "Hurray on Waveney". (I hope that rhymes in english  :D)

WOW!!!

Indeed it does rhyme, and Waveney is a hero!

waveney

  • Hero Member
  • *****
  • Posts: 5214
  • Irregular Galaxy Hunter
    • View Profile
Re: Peas Project
« Reply #66 on: July 13, 2008, 09:37:22 am »
Watch this space (7 5 4 1 websites left to move first)
« Last Edit: July 13, 2008, 10:50:31 am by waveney »
Join the Irregular Classifiers
We all help at the cutting edge of ignorance.

waveney

  • Hero Member
  • *****
  • Posts: 5214
  • Irregular Galaxy Hunter
    • View Profile
Re: Peas Project
« Reply #67 on: July 13, 2008, 01:01:44 pm »
Starting...
Join the Irregular Classifiers
We all help at the cutting edge of ignorance.

ElisabethB

  • Hero Member
  • *****
  • Posts: 13200
    • View Profile
Re: Peas Project
« Reply #68 on: July 13, 2008, 01:04:57 pm »
the suspense is killing me !  ;D

waveney

  • Hero Member
  • *****
  • Posts: 5214
  • Irregular Galaxy Hunter
    • View Profile
Re: Peas Project
« Reply #69 on: July 13, 2008, 02:03:14 pm »
Under test, one error found in data, one small error being chased now.  2174 objects in the list...
Join the Irregular Classifiers
We all help at the cutting edge of ignorance.

waveney

  • Hero Member
  • *****
  • Posts: 5214
  • Irregular Galaxy Hunter
    • View Profile
Re: Peas Project
« Reply #70 on: July 13, 2008, 02:12:55 pm »
Ok, Peas project about to start.  Go to: Pea Hunting
this uses the same login/password as Merger Hunting, so if you merger hunt, you will not need to re-register.

I have given you three choices: Green, Greenish, Not Green

Have fun, there are only 2174 images to check.

Reminder - these are Peas:

« Last Edit: July 14, 2008, 12:50:45 pm by waveney »
Join the Irregular Classifiers
We all help at the cutting edge of ignorance.

zookeeperKevin

  • Galaxy Zoo Keeper
  • Admin
  • Hero Member
  • *****
  • Posts: 2020
    • View Profile
Re: Peas Project
« Reply #71 on: July 13, 2008, 02:24:01 pm »
You guys are AWESOME!

ElisabethB

  • Hero Member
  • *****
  • Posts: 13200
    • View Profile
Re: Peas Project
« Reply #72 on: July 13, 2008, 02:34:30 pm »
peas it is then for Sunday dinner !  ;D

Alice

  • Global Moderator
  • Hero Member
  • ****
  • Posts: 31782
    • View Profile
Re: Peas Project
« Reply #73 on: July 13, 2008, 02:43:55 pm »
Waveny, I might just open a bottle of wine today simply so that I can toast you every time I take a sip! :o :o :o :o :o

(P.S. Where are the Knights of Ni when you need them? "We will say 'Ni!' again to you if you do not ap-pea-se us . . .")
« Last Edit: July 13, 2008, 02:46:10 pm by Alice »

waveney

  • Hero Member
  • *****
  • Posts: 5214
  • Irregular Galaxy Hunter
    • View Profile
Re: Peas Project
« Reply #74 on: July 13, 2008, 02:45:58 pm »
I was disappointed it took me so long to setup...  It should have been about 20 minutes...  >:(
Join the Irregular Classifiers
We all help at the cutting edge of ignorance.