Plotting Rotation Curves

with plotly.graph_objects

1. Import packages
2. Import data
   • Trim data if needed
   • Define radius (arcsec or kpc)
   • Define radial velocity (km/s)
3. Plot
   • Add photo of galaxy, adjust size for correct scaling
     • Add distance measure from finding chart tool, or use coordinates in fits header, to make a distance ruler to match to the plot
   • Save interactive plot with fig.write_html(filename).

import pandas as pd
import numpy as np
import plotly.graph_objects as go
import urllib.request
from PIL import Image

# Unknown source of data
dat = pd.read_csv('./Labs/DarkMatter/ngc_134_rc.dat',comment='#',index_col=False,sep='\s+')
V_tot = dat['Vc']
r_arcsec = dat['arcseconds']
name = 'NGC134'
V_r = 1596
H0 = 72
dist = (V_r/H0) # distance to galaxy in Mpc
r = (r_arcsec / 2.062e5) * (dist*1e3) # radius/distance fr center in kpc
V_c = V_tot - V_r
# correct for inclination
a = 7.56
b = 2.16
V_c = V_c / np.sqrt(1-(b/a)**2)


# Usually using an URL with source = "" in the plotly figure works, but it wasn't for these.  Instead, use urllib and image to define the images. 
urllib.request.urlretrieve('http://depts.washington.edu/astroed/GalaxyRotationCurves/ngc134-cropped.jpg', 'file_name')
img = Image.open('file_name')


# Plotting main points: 
fig = go.Figure() #Start graph_objects figure
fig.add_trace(go.Scatter(  #Add scatter plot, edit markers or lines
        x=r_arcsec,
        y=V_c,
        mode='markers',
        marker=dict(
            color='black',
            size=5,
            opacity=0.8,
            symbol='circle-open',line_width=2),name='')) 


# Plotting layout, labels, etc:
fig.update_layout(title={'text': name,
            'y':0.86,
            'x':0.5},
        xaxis={'title':"Distance from center (\")",
            'linecolor': 'rgba(0, 0, 0, 1)',
            'mirror': True, 
            'zeroline':False,
            'gridcolor':'lightgrey',
            'range':[-250,250]},
        yaxis={'title':'Rotational Velocity (km/s)',
            'linecolor': 'rgba(0, 0, 0, 1)',
            'mirror': True, 
            'zeroline':False,
            'gridcolor':'lightgrey'},
        plot_bgcolor = 'rgba(0, 0, 0, 0)',
        showlegend=False,
        width=700,
        height=590)

# Option to add finding chart / photo of galaxy, adjust so scaling is correct
fig.add_layout_image(
    dict(
        source=img,
        x=0.5,
        y=0.51))
fig.update_layout_images(dict(
        xref="paper",
        yref="paper",
        sizex=1,
        sizey=1,
        xanchor="center",
        yanchor="middle",
        opacity=0.8,
        layer="below"))

fig.show();
filename = './'+name+'rc.pdf'
# fig.write_html('./'+name+'rc.html')

# This is for reading the DeBlok rotation curve files;

# # @ARTICLE{2002A&A...385..816D,
#        author = {{de Blok}, W.~J.~G. and {Bosma}, A.},
#         title = "{High-resolution rotation curves of low surface brightness galaxies}",
#       journal = {\aap},
#      keywords = {GALAXIES: STRUCTURE, GALAXIES: KINEMATICS AND DYNAMICS, GALAXIES: HALOS, Astrophysics},
#          year = 2002,
#         month = apr,
#        volume = {385},
#         pages = {816-846},
#           doi = {10.1051/0004-6361:20020080},
# archivePrefix = {arXiv},
#        eprint = {astro-ph/0201276},
#  primaryClass = {astro-ph},
#        adsurl = {https://ui.adsabs.harvard.edu/abs/2002A&A...385..816D},
#       adsnote = {Provided by the SAO/NASA Astrophysics Data System}
# }

cols=('name','Angular Radius', #in arcsec already
      'Physical radius using adopted distance',
      'Rotation velocity of gas component',
      'Rotation velocity of disk',
      'Rotation velocity','Error in rotation velocity')
dat = pd.read_csv('./Labs/DarkMatter/DeBlokRC/procurve.dat',
                  comment='#',
                  sep='\s+',
                  header=None,index_col=False,
                  names=cols)
data = pd.DataFrame(dat)
names = data.name.unique()

# Example for plotting and artificially mirroring the DeBlok data
name = 'UGC3137'
rvel = data[data.name==name]['Rotation velocity'].values   
rang = data[data.name==name]['Angular Radius'].values    
rkpc = data[data.name==name]['Physical radius using adopted distance'].values 

rangrev = -rang[::-1]
rang_mirrored = np.empty(2*len(rvel))
rang_mirrored[:len(rvel)] = rangrev
rang_mirrored[len(rvel):] = rang
rvelopp = -rvel[::-1]
rvel_mirrored=np.empty(2*len(rvel))
rvel_mirrored[:len(rvel)] = rvelopp
rvel_mirrored[len(rvel):] = rvel




urllib.request.urlretrieve('http://depts.washington.edu/astroed/GalaxyRotationCurves/ugc3137-cropped.jpg', 'file_name')
img = Image.open('file_name')


fig = go.Figure()
fig.add_trace(go.Scatter(
        x=rang_mirrored,
        y=rvel_mirrored,
        mode='markers',
        marker=dict(
            color='black',
            size=5,
            opacity=0.7,
            symbol='circle-open',line_width=2),name='')) 

fig.update_layout(title={'text': name,
            'y':0.86,
            'x':0.5},
        xaxis={'title':"Distance from center (\")",
            'linecolor': 'rgba(0, 0, 0, 1)',
            'mirror': True, 
            'zeroline':False,
            'gridcolor':'lightgrey',
            'range':[-100,100]}, #change range as needed
        yaxis={'title':'Rotational Velocity (km/s)',
            'linecolor': 'rgba(0, 0, 0, 1)',
            'mirror': True, 
            'zeroline':False,
            'gridcolor':'lightgrey'},
        plot_bgcolor = 'rgba(0, 0, 0, 0)',
        showlegend=False,
        width=700,
        height=590)




fig.add_layout_image(
    dict(
        source=img,
        x=0.5,
        y=0.5))
fig.update_layout_images(dict(
        xref="paper",
        yref="paper",
        sizex=1,
        sizey=1,
#            sizex=3.6,
#         sizey=3.6,
        xanchor="center",
        yanchor="middle",
        opacity=0.8,
        layer="below"))


fig.show();

# fig.write_html('./'+name+'rc.html')

# Example 3:
name = 'NGC3274'
rvel = data[data.name==name]['Rotation velocity'].values   
rang = data[data.name==name]['Angular Radius'].values    
rkpc = data[data.name==name]['Physical radius using adopted distance'].values 

rangrev = -rang[::-1]
rang_mirrored = np.empty(2*len(rvel))
rang_mirrored[:len(rvel)] = rangrev
rang_mirrored[len(rvel):] = rang
rvelopp = -rvel[::-1]
rvel_mirrored=np.empty(2*len(rvel))
rvel_mirrored[:len(rvel)] = rvelopp
rvel_mirrored[len(rvel):] = rvel




urllib.request.urlretrieve('http://depts.washington.edu/astroed/GalaxyRotationCurves/ngc3274-cropped.jpg', 'file_name')
img = Image.open('file_name')


fig = go.Figure()
fig.add_trace(go.Scatter(
        x=rang_mirrored,
        y=rvel_mirrored,
        mode='markers',
        marker=dict(
            color='black',
            size=5,
            opacity=0.7,
            symbol='circle-open',line_width=2),name='')) 

fig.update_layout(title={'text': name,
            'y':0.86,
            'x':0.5},
        xaxis={'title':"Distance from center (\")",
            'linecolor': 'rgba(0, 0, 0, 1)',
            'mirror': True, 
            'zeroline':False,
            'gridcolor':'lightgrey',
            'range':[-100,100]}, #change range as needed
        yaxis={'title':'Rotational Velocity (km/s)',
            'linecolor': 'rgba(0, 0, 0, 1)',
            'mirror': True, 
            'zeroline':False,
            'gridcolor':'lightgrey'},
        plot_bgcolor = 'rgba(0, 0, 0, 0)',
        showlegend=False,
        width=700,
        height=590)




fig.add_layout_image(
    dict(
        source=img,
        x=0.5,
        y=0.5))
fig.update_layout_images(dict(
        xref="paper",
        yref="paper",
        sizex=1,
        sizey=1,
#            sizex=3.6,
#         sizey=3.6,
        xanchor="center",
        yanchor="middle",
        opacity=0.8,
        layer="below"))


fig.show();

# fig.write_html('./'+name+'rc.html')

# Example 4
name = 'UGC1281'
rvel = data[data.name==name]['Rotation velocity'].values   
rang = data[data.name==name]['Angular Radius'].values    
rkpc = data[data.name==name]['Physical radius using adopted distance'].values 

rangrev = -rang[::-1]
rang_mirrored = np.empty(2*len(rvel))
rang_mirrored[:len(rvel)] = rangrev
rang_mirrored[len(rvel):] = rang
rvelopp = -rvel[::-1]
rvel_mirrored=np.empty(2*len(rvel))
rvel_mirrored[:len(rvel)] = rvelopp
rvel_mirrored[len(rvel):] = rvel


fig = go.Figure()
fig.add_trace(go.Scatter(
        x=rang_mirrored,
        y=rvel_mirrored,
        mode='markers',
        marker=dict(
            color='black',
            size=5,
            opacity=0.7,
            symbol='circle-open',line_width=2),name='')) 

# Layout:
fig.update_layout(title={'text': name,
            'y':0.86,
            'x':0.5},
        xaxis={'title':"Distance from center (\")",
            'linecolor': 'rgba(0, 0, 0, 1)',
            'mirror': True, 
            'zeroline':False,
            'gridcolor':'lightgrey',
            'range':[-205,205]}, #change range as needed
        yaxis={'title':'Rotational Velocity (km/s)',
            'linecolor': 'rgba(0, 0, 0, 1)',
            'mirror': True, 
            'zeroline':False,
            'gridcolor':'lightgrey'},
        plot_bgcolor = 'rgba(0, 0, 0, 0)',
        showlegend=False,
        width=700,
        height=590)



urllib.request.urlretrieve('http://depts.washington.edu/astroed/GalaxyRotationCurves/ugc1281-cropped.jpg', 'file_name')
img = Image.open('file_name')

fig.add_layout_image(
    dict(
        source=img,
        x=0.5,
        y=0.515))
fig.update_layout_images(dict(
        xref="paper",
        yref="paper",
#         sizex=3.3,
#         sizey=3.3,
        sizex=1,
        sizey=1,
        xanchor="center",
        yanchor="middle",
        opacity=0.8,
        layer="below"))


fig.show();

# fig.write_html('./'+name+'rc.html')

# Example 4
name = 'UGC1281'
rvel = data[data.name==name]['Rotation velocity'].values   
rang = data[data.name==name]['Angular Radius'].values    
rkpc = data[data.name==name]['Physical radius using adopted distance'].values 

rangrev = -rang[::-1]
rang_mirrored = np.empty(2*len(rvel))
rang_mirrored[:len(rvel)] = rangrev
rang_mirrored[len(rvel):] = rang
rvelopp = -rvel[::-1]
rvel_mirrored=np.empty(2*len(rvel))
rvel_mirrored[:len(rvel)] = rvelopp
rvel_mirrored[len(rvel):] = rvel


fig = go.Figure()
fig.add_trace(go.Scatter(
        x=rang_mirrored,
        y=rvel_mirrored,
        mode='markers',
        marker=dict(
            color='black',
            size=5,
            opacity=0.7,
            symbol='circle-open',line_width=2),name='')) 

# Layout:
fig.update_layout(title={'text': name,
            'y':0.86,
            'x':0.5},
        xaxis={'title':"Distance from center (\")",
            'linecolor': 'rgba(0, 0, 0, 1)',
            'mirror': True, 
            'zeroline':False,
            'gridcolor':'lightgrey',
            'range':[-205,205]}, #change range as needed
        yaxis={'title':'Rotational Velocity (km/s)',
            'linecolor': 'rgba(0, 0, 0, 1)',
            'mirror': True, 
            'zeroline':False,
            'gridcolor':'lightgrey'},
        plot_bgcolor = 'rgba(0, 0, 0, 0)',
        showlegend=False,
        width=700,
        height=590)


fig.add_layout_image(
    dict(
        source='../../Work/cropped-imgs/ugc1281-cropped.jpg',
        x=0.5,
        y=0.5))
fig.update_layout_images(dict(
        xref="paper",
        yref="paper",
#         sizex=3.3,
#         sizey=3.3,
        sizex=1,
        sizey=1,
        xanchor="center",
        yanchor="middle",
        opacity=0.8,
        layer="below"))


fig.show();

# fig.write_html('./'+name+'rc.html')

# To print all rcs from entire list:

for galaxy in names:
    rvel = data[data.name==galaxy]['Rotation velocity']    
    rkpc = data[data.name==galaxy]['Physical radius using adopted distance']    
    
    fig = go.Figure()
    fig.add_trace(go.Scatter(
            x=rkpc,
            y=rvel,
            mode='markers',
            marker=dict(
                color='black',
                size=5,
                opacity=0.7,
                symbol='circle-open',line_width=2),name='')) 

    # Layout:
    fig.update_layout(title={'text': galaxy,
                'y':0.86,
                'x':0.5},
            xaxis={'title':"Distance from center (kpc)",
                'linecolor': 'rgba(0, 0, 0, 1)',
                'mirror': True, 
                'zeroline':False},
            yaxis={'title':'Rotational Velocity (km/s)',
                'linecolor': 'rgba(0, 0, 0, 1)',
                'mirror': True, 
                'zeroline':False},
            plot_bgcolor = 'rgba(0, 0, 0, 0)',
            showlegend=False,
            width=600,
            height=600)

    # fig.write_html('./'+name+'rc.html')
    fig.show();