Undergraduate ALFALFA

Answers to scavenger2 questions

  1. Plot the location of galaxies with different labels for velocity:




    pro SQL



    ; You need to know the minimum and the maximum velocities in the array and you use it doing

    ; mayor = max(v) and

    ; menor = min(v)

    ; You also need to know how many elements the array has' youcan do that with

    ; numero = n_elements(v)





    openr,lun, 'resultsmall.csv',/get_lun

    data = fltarr(15,15)

    readf,lun,data

    ;Here it read the data from the SQL Search







    x = data[0,*]

    y = data[1,*]

    ; we pick out R.A. and Dec as our x and y axis respectively



    c = 2.99792458E8

    z = data[2,*]

    v=( z*2.99792458E5)

    ; It translates the redshifs to velocities



    plot,x,y,/nodata,xrange=[210,208],yrange=[5.0,6.0],title= 'Distribution of galaxies in the NGC 5364 group from SQL',xtitle ='R.A. (deg)',ytitle=' Dec (deg)'

    ; It plots the box with no data in it







    index = where( (v gt 500) and (v le 1000))

    for i= 0,14 do a= data[0,index]

    for i= 0,14 do b= data[1,index]

    oplot, a,b,psym=1

    ; from here on the program picks out the values of v that fall into a certain range and overplots them over the empty box with a distinctive symbol



    index2 = where((v gt 1000) and(v le 3000))

    for i= 0,14 do c= data[0,index2]

    for i= 0,14 do d= data[1,index2]

    oplot,c,d,psym=2



    index3 = where((v gt 3000) and(v le 6000))

    for i= 0,14 do e= data[0,index3]

    for i= 0,14 do f= data[1,index3]

    oplot,e,f,psym=4



    index4 = where((v gt 6000) and(v le 9000))

    for i= 0,14 do g= data[0,index4]

    for i= 0,14 do h= data[1,index4]

    oplot,g,h,psym=5



    index5 = where((v gt 9000)and (v le 12000))

    for i= 0,14 do j= data[0,index5]

    for i= 0,14 do k= data[1,index5]

    oplot,j,k,psym=6



    index6 = where(v gt 12000)

    for i= 0,14 do l= data[0,index6]

    for i= 0,14 do m= data[1,index6]

    oplot,l,m,psym=7

    legend, ['v : (500-1000]','v : (1000-3000]','v : (3000-6000]','v : (6000-9000]','v : (9000-12000]','v : (> 12000)'],psym = [1,2,4,5,6,7]

    ; Finally, it adds a legend to the graph specifying the v value ranges that correspond to the symbols of the data points.

    set_plot, 'ps'

    device, filename = 'SQLplot.ps'

    plot,x,y,/nodata,xrange=[210,208],yrange=[5.0,6.0],title= 'Distribution of galaxies in the NGC 5364 group from SQL',xtitle ='R.A. (deg)',ytitle=' Dec (deg)'

    oplot, a,b,psym=1

    oplot,c,d,psym=2

    oplot,e,f,psym=4

    oplot,g,h,psym=5

    oplot,j,k,psym=6

    oplot,l,m,psym=7

    legend, ['v : (500-1000]','v : (1000-3000]','v : (3000-6000]','v : (6000-9000]','v : (9000-12000]','v : (> 12000)'],psym = [1,2,4,5,6,7]

    device,/close

    set_plot, 'x'



    end


    galaxies