Palomar Survey

DESCRIPTION	Using the echarts4r package to create an interactive BPT diagram that includes as many annotations or tooltips as possible the help spectroscopy supernovices understand the data they’re looking at better.
TOOLS	RStudio, Quarto, HTML, CSS
PROJECT_TYPE	Data manipulation, Data analysis, Data visualization, Interactive charts
LINKS	Github Repo

 

 

Goal

This is the first project where I felt a little less than a subject matter novice. This was my first time even hearing the word ‘spectroscopic’, so I really needed to get a basic understanding of the domain and some of the conventions of visualising its data.

Googling what type of charts are generated in spectroscopy produced a variety of interesting results. The one that stood out to me was the BPT diagram (Baldwin, Phillips & Terlevich) - same type of diagram as the sample image provided with the dataset.

So much about what I was seeing wasn’t clicking, so I set out to create a simple chart with the echarts4r package that would be covered with annotations that could be helpful for people who aren’t familiar with the subject matter.

 

 

Process

Before I could begin creating the chart, I first needed to decide what I wanted it to convey. When in doubt, I like looking at the categorical data - in this case whether the galaxy is Seyfert, LINER, or Transition - and mapping them together on a single canvas to see if a relationship/story reveals itself (visually).

 

Chart Type

The BPT diagram is essentially a scatterplot with a series of lines the demarcate thresholds that help to classify galaxies by their underlying energy source: Star-forming galaxies (photoionization from massive young stars) versus Active Galactic Nuclei (AGN) like Seyferts or LINERs (supermassive black hole accretion or shock heating).
Looking at the data dictionary, I narrowed down my variable choices by selecting for any mention of the BPT diagram or galaxy type.

 

log_oiii_hb	Dereddened [O III] 5007 / H-beta intensity ratio. Higher values indicate higher ionization. Used on the y-axis of BPT diagrams.
log_nii_ha	Dereddened [N II] 6583 / H-alpha intensity ratio. The primary x-axis of the classic BPT diagnostic diagram.

 

With the axes selected, I next needed another variable as an aspect of the galaxies. helio_velocity_km_s was actually the first one I gravitated* to before even deciding on a chart type - because it’s such a cool name for a variable, and it created this picture of the sun and speed in my mind. This is the variable I could use for filtering by distance and observe which categories occupy which positions on the canvas.

The idea wasn’t to make a grand/thoughtful observation - I really don’t know this field, I challenged myself not to let an LLM give me the illusion of being able to portray otherwise. My job was simply to map the chosen variables in a readable way, using simpler language and keeping the cognitive load as low as possible.

 

 

Final Presentation

 # loading libraries
 suppressPackageStartupMessages({
   library(here)
   library(readr)
   library(dplyr)
   library(echarts4r)
   library(htmltools)
   library(htmlwidgets)
   })



# 1. Bringing in the data:
palomar_survey <- read_csv("data/tt_2026_08_11/palomar_survey.csv")

# 2. Clean survey data & compute geometric 4-region BPT boundaries
df_bpt <- palomar_survey |>
  filter(
    !is.na(log_nii_ha), 
    !is.na(log_oiii_hb), 
    !is.na(helio_velocity_km_s),
    !is.na(activity_type),
    activity_type != "Absorption"
  ) |>
  mutate(
    dist_mpc = round(abs(helio_velocity_km_s) / 70, 1),
    
    # 2.1 Theoretical curve y-values evaluated at each point's x coordinate
    kauffmann_y = if_else(log_nii_ha < 0.05, 0.61 / (log_nii_ha - 0.05) + 1.30, NA_real_),
    kewley_y    = if_else(log_nii_ha < 0.47, 0.61 / (log_nii_ha - 0.47) + 1.19, NA_real_),
    seyfert_y   = 1.01 * log_nii_ha + 0.48,
    
    # 2.2 Coordinate-based BPT classification
    bpt_region = case_when(
      # 2.2.1. Pure Star-Forming (far left, below Kauffmann line)
      log_nii_ha < 0.05 & log_oiii_hb < kauffmann_y ~ "Star-Forming Zone",
      
      # 2.2.2. Seyfert (above Kewley limit/line AND above Seyfert/LINER line)
      (log_nii_ha >= 0.47 | log_oiii_hb >= kewley_y) & log_oiii_hb >= seyfert_y ~ "Seyfert Zone",
      
      # 2.2.3. LINER (far right x >= 0.47 AND below Seyfert/LINER line)
      log_nii_ha >= 0.47 & log_oiii_hb < seyfert_y ~ "LINER Zone",
      
      # 2.2.4. Transition Zone (composite zone between Kauffmann & LINER boundaries)
      TRUE ~ "Transition Zone"
    ),
    
    bpt_region = factor(
      bpt_region, 
      levels = c("Star-Forming Zone", "Transition Zone", "Seyfert Zone", "LINER Zone")
    ),
    
    tooltip_label = sprintf(
      "<div style='font-family: sans-serif; width: 210px; white-space: normal; word-wrap: break-word;'>
        <div style='font-weight: bold; font-size: 22px; color: #111; margin-bottom: 4px;'>%s</div>
        <div style='font-size: 18px; color: #666; margin-bottom: 6px;'>Catalog Type: %s</div>
        <div style='border-top: 1px solid #eee; padding-top: 4px; font-size: 16px; line-height: 1.4;'>
          <div><span style='color: #888;'>Zone:</span> <b>%s</b></div>
          <div><span style='color: #888;'>Distance:</span> <b>%.1f Mpc</b></div>
        </div>
      </div>",
      galaxy_name, activity_type, bpt_region, dist_mpc
    )
  )

min_dist <- min(df_bpt$dist_mpc, na.rm = TRUE)
max_dist <- max(df_bpt$dist_mpc, na.rm = TRUE)

# 3. Generating Boundary Line Data Frames

# 3.1 Kauffmann Line (Pure Starburst boundary)
df_kauffmann <- data.frame(x = seq(-0.2, 0.02, length.out = 100)) |>
  mutate(y = 0.61 / (x - 0.05) + 1.30) |>
  filter(y >= -0.2)

# 3.2 Kewley Line (Theoretical maximum starburst limit)
df_kewley <- data.frame(x = seq(-0.2, 0.43, length.out = 100)) |>
  mutate(y = 0.61 / (x - 0.47) + 1.19) |>
  filter(y >= -0.2)

# 3.3 Seyfert / LINER Divider
df_seyfert <- data.frame(x = seq(0, 0.75, length.out = 100)) |>
  mutate(y = 1.01 * x + 0.48)


# 4. Standard Grey Info Badges (Zones + Axes)
df_info_badges <- data.frame(
  x = c(
    0.35,  # Seyfert Zone
    0.68,  # LINER Zone
    -0.10, # Starburst Zone
    0.25,  # Transition Zone
    -0.18, # Y-Axis Info
    0.73,  # X-Axis Info
    0.10   # Seyfert / LINER Divider
  ),
  y = c(
    1.32,  # Seyfert Zone
    0.52,  # LINER Zone
    0.30,  # Starburst Zone
    0.35,  # Transition Zone
    1.44,  # Y-Axis Info
    -0.12, # X-Axis Info
    0.70   # Seyfert / LINER Divider
  ),
  info_card = c(
    # SEYFERT EXPLANATION
    "<div style='font-family: sans-serif; width: 360px; white-space: normal; word-wrap: break-word; padding: 2px;'>
      <div style='font-weight: bold; font-size: 20px; color: #9013FE; margin-bottom: 6px;'>Seyfert Galaxies</div>
      <p style='font-size: 16px; color: #333; line-height: 1.45; margin: 0 0 8px 0;'>
        <b>What powers these galaxies?</b> An actively feeding supermassive black hole emitting ultraviolet light and X-rays.
      </p>
      <p style='font-size: 16px; color: #555; line-height: 1.45; margin: 0;'>
        <b>Why do they plot here?</b> High-energy radiation strips electrons from oxygen atoms ([O III]), pushing them above the Seyfert/LINER divider.
      </p>
    </div>",
    
    # LINER EXPLANATION
    "<div style='font-family: sans-serif; width: 360px; white-space: normal; word-wrap: break-word; padding: 2px;'>
      <div style='font-weight: bold; font-size: 20px; color: #4A90E2; margin-bottom: 6px;'>LINER Galaxies</div>
      <p style='font-size: 16px; color: #333; line-height: 1.45; margin: 0 0 8px 0;'>
        <b>What powers these galaxies?</b> Low-accretion black holes, shockwaves, or evolved star populations.
      </p>
      <p style='font-size: 16px; color: #555; line-height: 1.45; margin: 0;'>
        <b>Why do they plot here?</b> High nitrogen emission shifted right (x &ge; 0.47), but lacking top-tier oxygen ionization energy.
      </p>
    </div>",
    
    # STARBURST EXPLANATION
    "<div style='font-family: sans-serif; width: 360px; white-space: normal; word-wrap: break-word; padding: 2px;'>
      <div style='font-weight: bold; font-size: 20px; color: #7ED321; margin-bottom: 6px;'>Starburst Nurseries</div>
      <p style='font-size: 16px; color: #333; line-height: 1.45; margin: 0 0 8px 0;'>
        <b>What powers these galaxies?</b> Massive young star formation (x &lt; 0.05).
      </p>
    </div>",
    
    # TRANSITION EXPLANATION
    "<div style='font-family: sans-serif; width: 360px; white-space: normal; word-wrap: break-word; padding: 2px;'>
      <div style='font-weight: bold; font-size: 20px; color: #F5A623; margin-bottom: 6px;'>Transition / Composite Zone</div>
      <p style='font-size: 16px; color: #333; line-height: 1.45; margin: 0 0 8px 0;'>
        <b>What powers these galaxies?</b> A hybrid mix of starlight ionization and weak central black hole activity.
      </p>
      <p style='font-size: 16px; color: #555; line-height: 1.45; margin: 0;'>
        <b>Why do they plot here?</b> They form the main cluster between pure H II starbursts and pure AGN excitation regimes.
      </p>
    </div>",
    
    # Y-AXIS
    "<div style='font-family: sans-serif; width: 360px; white-space: normal; word-wrap: break-word; padding: 2px;'>
      <div style='font-weight: bold; font-size: 18px; color: #111; margin-bottom: 4px;'>Vertical Axis: log([O III] / Hβ)</div>
      <p style='font-size: 16px; color: #444; line-height: 1.4; margin: 0;'>
        Measures total <b>ionization energy</b>.
      </p>
    </div>",
    
    # X-AXIS
    "<div style='font-family: sans-serif; width: 360px; white-space: normal; word-wrap: break-word; padding: 2px;'>
      <div style='font-weight: bold; font-size: 18px; color: #111; margin-bottom: 4px;'>Horizontal Axis: log([N II] / Hα)</div>
      <p style='font-size: 16px; color: #444; line-height: 1.4; margin: 0;'>
        Measures the <b>gas excitation mechanism</b>.
      </p>
    </div>",
    
    # SEYFERT / LINER DIVIDER
    "<div style='font-family: sans-serif; width: 360px; white-space: normal; word-wrap: break-word; padding: 2px;'>
      <div style='font-weight: bold; font-size: 20px; color: #111; margin-bottom: 6px;'>Seyfert / LINER Divider</div>
      <p style='font-size: 16px; color: #333; line-height: 1.45; margin: 0;'>
        Separates high-energy Seyfert AGN (above) from lower-energy LINERs (below).
      </p>
    </div>"
  )
)

# 5. Render Final Explorer
dist_scale <- function(x) { 5 + (x / max_dist) * 16 }
  
# Generating the chart
palomar_interactive_viz <- 
df_bpt |>
  group_by(bpt_region, .drop = FALSE) |>
  e_charts(
    log_nii_ha, 
    height = 620
  ) |>
  e_scatter(
    log_oiii_hb,
    size = dist_mpc,
    bind = tooltip_label,
    scale = dist_scale,
    itemStyle = list(
      borderColor = "#443",
      borderWidth = 1 
    )
  ) |>
  
  e_color(c("#7ED321", "#F5A623", "#9013FE", "#4A90E2"), background = "#f8f9fa") |>
  e_visual_map(
    min = min_dist,
    max = max_dist,
    dimension = 2,
    seriesIndex = c(0, 1, 2, 3),
    top = 30,
    orient = "horizontal",
    left = "center",
    text = c("Far (Mpc)", "Near (Mpc)"),
    textStyle = list(color = "#444444", fontSize = 16, fontWeight = "bold"),
    itemWidth = 14,
    itemHeight = 160,
    target = list(inRange = list(opacity = 0.85), outOfRange = list(opacity = 0.05)),
    controller = list(inRange = list(color = c("#888888", "#888888")))
  ) |>
  
  # Kauffmann Line
  e_data(df_kauffmann, x) |>
  e_line(
    y, name = "Kauffmann Line", symbol = "none", legend = FALSE,
    lineStyle = list(type = "dashed", width = 1.5, color = "#888888")
  ) |>
  
  # Kewley Line
  e_data(df_kewley, x) |>
  e_line(
    y, name = "Kewley Line", symbol = "none", legend = FALSE,
    lineStyle = list(type = "dashed", width = 2, color = "#333333")
  ) |>
  
  # Seyfert / LINER Divider
  e_data(df_seyfert, x) |>
  e_line(
    y, name = "Seyfert / LINER Divider", symbol = "none", legend = FALSE,
    lineStyle = list(type = "dotted", width = 2, color = "#333333")
  ) |>
  
  # Badges
  e_data(df_info_badges, x) |>
  e_scatter(
    y,
    bind = info_card,
    name = "Info Badges",
    legend = FALSE,
    symbol = "path://M12 2C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm1 15h-2v-6h2v6zm0-8h-2V7h2v2z",
    symbol_size = 25,
    itemStyle = list(color = "#9CA3AF"),
    emphasis = list(
      itemStyle = list(color = "#1F2937"),
      scale = 1.25
    )
  ) |>
  
  e_x_axis(
    name = "log([N II] / Hα)",
    nameLocation = "end",
    name_gap = 28, 
    nameTextStyle = list(color = "#666666", fontSize = 16, fontWeight = "bold"),
    axisLabel = list(color = "#666666", margin = 20, fontSize = 14),
    axisLine = list(lineStyle = list(width = 2, color = "#666666")),
    min = -0.2, 
    max = 0.75
  ) |>
  e_y_axis(
    name = "log([O III] / Hβ)",
    nameLocation = "end",
    nameGap = 20,
    nameTextStyle = list(color = "#666666", fontSize = 16, fontWeight = "bold"),
    axisLabel = list(color = "#666666", margin = 20, fontSize = 14),
    axisLine = list(lineStyle = list(width = 2, color = "#666666")),
    min = -0.2, 
    max = 1.5
  ) |>
  e_legend(
    left = "center",
    top = 100,
    textStyle = list(fontSize = 14)
  ) |>
  e_grid(
    top = 210, 
    bottom = 25
  ) |>
  e_tooltip(
    formatter = htmlwidgets::JS("function(params) { return params.name; }"),
    backgroundColor = "#ffffff",
    borderColor = "#cccccc",
    borderWidth = 1,
    extraCssText = "box-shadow: 0 4px 16px rgba(0,0,0,0.15); border-radius: 8px; padding: 12px;"
  )




 # presentation base container (the canvas)
 palomar_survey_viz <- 
   htmltools::tagList(
   tags$div(
     style = "
       background-color: white;
       padding: 50px;
       margin-left: 20px;
       margin-right: 50px;
       margin-bottom: 20px;
       ",
     
   # responsive flexbox for the headline
  tags$div(
    style = "
     display: flex; 
     flex-wrap: wrap; 
     gap: 30px; 
     align-items: flex-start; 
     width: 100%;
   ", 
    
     # headline and subtitle wrapper
     tags$div(
       style = "
         flex: 1;
         min-width: 400px; 
         display: flex; 
         flex-direction: column;
         padding-bottom: 20px;
       ",
       # title
       tags$div(
         style = "text-align:left; margin-bottom: 15px; font-family: Plus Jakarta Sans; font-weight: 950; line-height: 1.1;",
         HTML(
           "<span style='color:#666666; font-size:26px;'>What Powers Nearby Galaxies? Most Are </span> <span style='color:#F5A623; font-size:26px;'> Hybrids</span> <span style='color:#666666; font-size:26px;'>, Not </span> <span style='color:#9013FE; font-size:26px;'>Violent </span> "
       )
      ),
       # subtitle
       tags$div(
         style = "text-align:left; font-family: Inter, sans-serif; font-size:18px; font-weight: 400; # color:#666666; line-height:1.4; margin-bottom:0px;",
         HTML(
           "Galaxies generate energy through newborn stars, central black holes, or a mix of both. In our local universe, pure <span style='color:#7ED321; font-weight:bold;'>starbursts</span> are rare. Most galaxies sit in a hybrid <span style='color:#F5A623; font-weight:bold;'>Transition zone</span> or idle on starving black hole diets in the <span style='color:#4A90E2; font-weight:bold;'>LINER zone</span>, while only a small fraction actively rage as high-energy <span style='color:#9013FE; font-weight:bold;'>Seyferts</span>."
         )
       )
     )
  ),
 
# responsive flexbox that holds the chart
tags$div(
  style = "
    display: flex; 
    flex-wrap: wrap; 
    gap: 0px; 
    align-items: flex-start; 
    width: 100%;
  ",
  
    # the chart
    palomar_interactive_viz
  
), # closing responsive flexbox that holds the chart
 
 
 
 # start of page footer with data and author details
 tags$div(
   style = "display: flex; justify-content: center; align-items: center; flex-wrap: wrap; margin-top: 50px; margin-bottom: 10px;",
   
   # data source wrapper to ensure it scales nicely
   tags$span(
     style = "display: inline-flex; align-items: center;",
     
     tags$span(
       "Data Source :",
       style = "color: #888; text-decoration: none; font-family: Plus Jakarta Sans; font-size: 14px; font-weight: 450; margin-right: 5px;"
     ),
 
     # tidy tuesday repo link
     tags$a(
       "Palomar Spectroscopic Survey of Nearby Galaxies via Tidy Tuesday (2026-32)",
       href = "[https://github.com/rfordatascience/tidytuesday/blob/main/data/2026/2026-08-04/readme.md](https://github.com/rfordatascience/tidytuesday/blob/main/data/2026/2026-08-11/readme.md)",
       target = "_blank",
       style = "color: #F5A623; text-decoration: none; font-family: Plus Jakarta Sans; font-size: 14px; font-weight: bold;"
     )
   ),
 
   # css margin spacer
   tags$span(style = "margin-left: 40px;"),
 
   # author social media handles wrapper
   tags$span(
     style = "display: inline-flex; align-items: center; gap: 20px;",
     
     # linkedin wrapper
     tags$span(
       style = "display: inline-flex; align-items: center; white-space: nowrap;",   
       
       # linkedin logo
       tags$img(
         HTML('<svg xmlns="[http://www.w3.org/2000/svg](http://www.w3.org/2000/svg)" width="18" height="18" fill="#F5A623"  class="bi bi-linkedin" viewBox="0 0 16 16">
       <path d="M0 1.146C0 .513.526 0 1.175 0h13.65C15.474 0 16 .513 16 1.146v13.708c0 .633-.526  1.146-1.175 1.146H1.175C.526 16 0 15.487 0 14.854zm4.943 12.248V6.169H2.542v7.225zm-1.2-8.212c.837 0  1.358-.554 1.358-1.248-.015-.709-.52-1.248-1.342-1.248S2.4 3.226 2.4 3.934c0 .694.521 1.248 1.327  1.248zm4.908 8.212V9.359c0-.216.016-.432.08-.586.173-.431.568-.878 1.232-.878.869 0 1.216.662 1.216  1.634v3.865h2.401V9.25c0-2.22-1.184-3.252-2.764-3.252-1.274 0-1.845.7-2.165  1.193v.025h-.016l.016-.025V6.169h-2.4c.03.678 0 7.225 0 7.225z"/>
     </svg>')
       ), 
 
       # linkedin link
       tags$a(
         "Ntobeko Sosibo",
         href = "[https://www.linkedin.com/in/ntobeko-sosibo/](https://www.linkedin.com/in/ntobeko-sosibo/)",
         target = "_blank",
         style = "margin-left: 10px; color: #888; text-decoration: none; font-family: 'Plus Jakarta Sans'; font-size: 14px; font-weight: 450;"
       )
     ),
       
     # github wrapper
     tags$span(
       style = "display: inline-flex; align-items: center; white-space: nowrap;",
 
       # github logo
       tags$img(
         HTML(
           '<svg xmlns="[http://www.w3.org/2000/svg](http://www.w3.org/2000/svg)" width="18" height="18" fill="#F5A623" class="bi bi-github" viewBox="0 0 16 16">
       <path d="M8 0C3.58 0 0 3.58 0 8c0 3.54 2.29 6.53 5.47 7.59.4.07.55-.17.55-.38  0-.19-.01-.82-.01-1.49-2.01.37-2.53-.49-2.69-.94-.09-.23-.48-.94-.82-1.13-.28-.15-.68-.52-.01-.53.63 -.01 1.08.58 1.23.82.72 1.21 1.87.87 2.33.66.07-.52.28-.87.51-1.07-1.78-.2-3.64-.89-3.64-3.95  0-.87.31-1.59.82-2.15-.08-.2-.36-1.02.08-2.12 0 0 .67-.21 2.2.82.64-.18 1.32-.27 2-.27s1.36.09 2  .27c1.53-1.04 2.2-.82 2.2-.82.44 1.1.16 1.92.08 2.12.51.56.82 1.27.82 2.15 0 3.07-1.87 3.75-3.65  3.95.29.25.54.73.54 1.48 0 1.07-.01 1.93-.01 2.2 0 .21.15.46.55.38A8.01 8.01 0 0 0 16 8c0-4.42-3.58-8-8-8"/>
     </svg>'
        )
       ),
       
       # github link
       tags$a(
         "afrikaniz3d-za",
         href = "[https://github.com/afrikaniz3d-za](https://github.com/afrikaniz3d-za)",
         target = "_blank",
         style = "margin-left: 10px; color: #888; text-decoration: none; font-family: Plus Jakarta Sans; font-size: 14px; font-weight: 450;"
         )
       ),
       
     # bluesky wrapper
     tags$span(
       style = "display: inline-flex; align-items: center; white-space: nowrap;",
 
       # bluesky logo
       tags$img(
         HTML(
           '<svg xmlns="[http://www.w3.org/2000/svg](http://www.w3.org/2000/svg)" width="18" height="18" fill="#F5A623" class="bi bi-bluesky" viewBox="0 0 16 16">
       <path d="M3.468 1.948C5.303 3.325 7.276 6.118 8 7.616c.725-1.498 2.698-4.29 4.532-5.668C13.855.955 16 .186 16 2.632c0 .489-.28 4.105-.444 4.692-.572 2.04-2.653 2.561-4.504 2.246 3.236.551 4.06 2.375 2.281 4.2-3.376 3.464-4.852-.87-5.23-1.98-.07-.204-.103-.3-.103-.218 0-.081-.033.014-.102.218-.379 1.11-1.855 5.444-5.231 1.98-1.778-1.825-.955-3.65 2.28-4.2-1.85.315-3.932-.205-4.503-2.246C.28 6.737 0 3.12 0 2.632 0 .186 2.145.955 3.468 1.948"/>
     </svg>'
         )
       ),
 
       # bluesky link
       tags$a(
         "afrikaniz3d",
         href = "[https://bsky.app/profile/afrikaniz3d.bsky.social](https://bsky.app/profile/afrikaniz3d.bsky.social)",
         target = "_blank",
         style = "margin-left: 10px; color: #888; text-decoration: none; font-family: Plus Jakarta Sans; font-size: 14px; font-weight: 450;"
               )
             ), # closing bluesky wrapper
 
     # mastodon wrapper
     tags$span(
       style = "display: inline-flex; align-items: center; white-space: nowrap;",
 
       # mastodon logo
       tags$img(
         HTML(
           '<svg xmlns="[http://www.w3.org/2000/svg](http://www.w3.org/2000/svg)" width="18" height="18" fill="#F5A623" class="bi bi-mastodon" viewBox="0 0 16 16">
       <path d="M11.19 12.195c2.016-.24 3.77-1.475 3.99-2.603.348-1.778.32-4.339.32-4.339 0-3.47-2.286-4.488-2.286-4.488C12.062.238 10.083.017 8.027 0h-.05C5.92.017 3.942.238 2.79.765c0 0-2.285 1.017-2.285 4.488l-.002.662c-.004.64-.007 1.35.011 2.091.083 3.394.626 6.74 3.78 7.57 1.454.383 2.703.463 3.709.408 1.823-.1 2.847-.647 2.847-.647l-.06-1.317s-1.303.41-2.767.36c-1.45-.05-2.98-.156-3.215-1.928a4 4 0 0 1-.033-.496s1.424.346 3.228.428c1.103.05 2.137-.064 3.188-.189zm1.613-2.47H11.13v-4.08c0-.859-.364-1.295-1.091-1.295-.804 0-1.207.517-1.207 1.541v2.233H7.168V5.89c0-1.024-.403-1.541-1.207-1.541-.727 0-1.091.436-1.091 1.296v4.079H3.197V5.522q0-1.288.66-2.046c.456-.505 1.052-.764 1.793-.764.856 0 1.504.328 1.933.983L8 4.39l.417-.695c.429-.655 1.077-.983 1.934-.983.74 0 1.336.259 1.791.764q.662.757.661 2.046z"/>
     </svg>'
         )
       ),
 
       # mastodon link
       tags$a(
         "afrikaniz3d",
         href = "[https://mastodon.social/@afrikaniz3d](https://mastodon.social/@afrikaniz3d)",
         target = "_blank",
         style = "margin-left: 10px; color: #888; text-decoration: none; font-family: Plus Jakarta Sans; font-size: 14px; font-weight: 450;"
               )
             ) # closing mastodon wrapper
           ) # closing social media handles wrapper
         ) # closing page footer
 
   )
 )
 
 palomar_survey_viz

What Powers Nearby Galaxies? Most Are Hybrids , Not Violent

Galaxies generate energy through newborn stars, central black holes, or a mix of both. In our local universe, pure starbursts are rare. Most galaxies sit in a hybrid Transition zone or idle on starving black hole diets in the LINER zone, while only a small fraction actively rage as high-energy Seyferts.

Data Source : Palomar Spectroscopic Survey of Nearby Galaxies via Tidy Tuesday (2026-32) Ntobeko Sosibo afrikaniz3d-za afrikaniz3d afrikaniz3d

 

There was no plan to create a static version of this presentation, but I imagine it would look very different if it were to maintain the amount of additional information that is tucked away behind the icons in this interactive version.

 

 

Reflecting

This project was a massive exercise in faith in a tool know for hallucination in many important regards. There were so many instances where the code would run and generate a plot, but it looked unlike many of the examples I was drawing inspiration from. This led to a lot of doubting my choice in ranges, filtering , and many other things. I continued and focused on building the supporting elements and injecting the information, trusting the process.

When it was done building it I was in a much better position to evaluate it. The main criteria was whether I felt it helped me understand why something was there, or whether it led me to look for additional information elsewhere because what I initially looked at wasn’t enough.

I’m enjoying this new period in my visualisations where I try to add as much simplified context as I can into the visualisations - the Basotho Wool is the most recent example where that really helped to give generic trade data more substance from the article that inspired the submission.

There’s always that moment, right at the end, where you think on how much more a project could be if you dedicated more time to it. I used to dread this feeling as a silent admission that I didn’t do enough or meet the mark, but I’ve also come to see it as a sign that I hit a stride while working that didn’t want to stop going.