Graphics Guide

Figure files should be submitted as Encapsulated PostScript (EPS) or Portable Document Format (PDF) and named as ‘f’ followed by the figure number, with an ‘.eps’ or ‘.pdf’ extension – for example, f1.eps, f2a.eps, f2b.eps, f3.eps, … . If you are using AASTeX, you should use AASTeX’s guide to include the figures in the TeX file. You should also embed the figures if you are using Microsoft Word to prepare your manuscript, but separate EPS or PDF figure files are still required at final submission.

Each figure file should consist of a single page. Authors are responsible for splitting multipage EPS and PDF files into many separate page files. This can be done automatically with Adobe Acrobat, manually with OS X’s Preview, or various free online tools.

Each figure set, animated, or interactive figure requires a static two dimensional representation rendered in the LaTeX/Word manuscript with a caption, etc. The static version (e.g., f1.pdf) should be uploaded like a regular figure and separate from the dynamic elements (HTML files, javascript libraries, data), which should be bundled as a zip file, e.g., fig01anim.zip, fig03int.zip, fig07set.zip, etc.

Preparing Your Files

We recommend that authors familiarize themselves with best practices for the creation and accessibility of scientific visualizations. Resources, including “Ten Simple Rules for Better Figures,” should be consulted to improve the impact and readability of your figures. Specifically, we call out Rougier et al.’s Rule 5: Do Not Trust the Defaults, and strongly encourage you to check the color defaults used by your preferred visualization software. This recommendation includes adopting color maps such as viridis, e.g., the default colormap in matplotlib 2.0 default, which is also available for R via CRAN, or cube-helix (Green 2011), which is available in some astronomy software tools such as AIPS or Aladin. The public domain R statistical and graphical software environment has flexible color options with 657 color names and palettes based on the Color Brewer, Hue-Saturation-Value and Hue-Chroma-Luminance systems. See R guidelines here (PDF) and here (PDF). Use of unsaturated colors is recommended when symbols overlap in crowded diagrams; this requires the PDF rather than EPS formats.

When we prepare the published version of your manuscript we may rearrange or resize the figures, so it is helpful if you can ensure that each figure or subfigure is in a separate file. If a figure is part of a lettered, multipart figure, place the letter within the box around the figure, not outside of it. If the letter cannot be placed within the box, lettered tags can be typeset. Page numbers, figure numbers, file information, etc., should not be included in figure files.

If you feel that figures in the published article must be sized or arranged in a certain way, please include a

readme.txt

file which describes your requirements; the Production Editor may contact you about this when the manuscript is accepted. Note that extra charges will be incurred if you decide to make alterations to figures at proof stage.

AASTeX Specific Advice: Instructions for structuring and placing figures using AASTeX are available.

General tips: Try to use only common fonts, such as Times, Helvetica, or Symbol, in figures. Spelling and use of numbers and units in figures should conform to usage in the body of the text and figure legends. A minimum of 6 pt. font size is acceptable. There should be consistency of appearance between the size of symbols and the size of type within a figure, and between the weight of the lines and the weight of type within the figures. Lines in figures should be at minimum 0.5 points, and if you use dotted or dashed lines you should check that the different sorts of lines are distinguishable when the figure is small.

Finding figures from ApJ/AJ articles: We have centralized all the figures in ApJ/AJ articles since ~1997 on our Astronomy Image Explorer (AIE) tool. The figures from your final article are posted at the AIE at publication sans embargo. They are provided in high resolution JPG, PDF, and PPT formats. As a result ADS has integrated these graphics into their new article landing pages (e.g., Mao et al. 2015) and link back to the AIE for each regular figure.

Figure Sets

A figure set is the frame work used to present a large compendia of similar images and graphical material in the HTML version of your final article. They have the added author benefit of simplifying quanta charges for related figures. Examples include identification charts, spectral libraries, model output, etc. Figure sets should be used when a single Figure exceeds four typeset print pages. The figure set functionality gives the reader the ability to quickly find specific images within the figure set sequence; thus, it is well suited in cases with many similar images.

To facilitate the layout of the final article, the figure set components and associated information need to be placed in the appropriate AASTeX/LaTeX mark up. This LaTeX markup is included in AASTeX >6.0, and allows you to craft individual titles and captions for each figure in the set. Figure sets must be mentioned explicitly by number and appear in correct numerical order in the body of the text. At least one image in a series must be displayed as an example static figure in the PDF version of the final article. The corresponding caption should indicate that additional images are available in the Figure set. For example,

“The complete figure set (11 images) is available in the online journal.

The example figure should be placed after the figure set mark up in the LaTeX file and created like a normal figure, e.g., \begin{figure}…. An online tool is available to help create the figure set mark up, as is a python script located at our github “Tools” repository.

Please submit all figure set figures in a single ZIP archive, e.g., fig01set.zip. Do not submit hundreds of figure set files individually (unless you think the referee needs to see them in the PDF used for peer-review). If you craft the LaTeX script yourself then also include it in the ZIP archive. The data editors will review this material post-acceptance.

For reference purposes, a list of published articles with figure sets (>950) in the AAS Journals can be found using our Astronomy Image Explorer by toggling the “Content Type => Figure sets” search facet.

Animations

We now support animations as regular figures in AAS Journal articles. Animated Figures are presented using a streaming YouTube like widget that works in all major browsers and on mobile platforms. As with regular Figures, animations can now be referred to by number, e.g., Figure 1, and subsequently linked in the final text. Readers click through from the static Figure to the streamed animation. We strongly recommend that a Figure contain one and only one animation due to issues readers face when interacting with multiple animations on a page.

Authors mark up an animated figure as they would any other figure in their manuscript file. You must supply a static representation of the animation in EPS/PDF format encoded as a regular figure to serve as an reference for the reader. The recommended way to do this is to provide a single “example” frame or grid of stills from the animation. Note that the content of the static and animated versions should closely agree. Other uses of animations that do not correspond to actual Figures in the text should be supplied as supplementary materials or hosted external to the journals in persistent third party repositories.

The caption of an animated figure must include text describing the animation and indicating that it is available in the HTML version of the final article. For instance, text such as “An animated version of this figure is available” should be followed with a short description of the animation itself — duration (in time or other units), how the content changes with time, video annotations, etc. This explicit description is critical for readers for whom the animation is inaccessible either due to a disability or offline access.

We strongly recommend animations be delivered in the MPEG-4 container, specifically encoded with the H264 codec. Other formats may be used, however using MPEG-4 will provide the most faithful rendering of your video in the journal article. A single movie per Figure should be optimized to fit within the typical Journal page and not overburden low bandwidth or mobile users. We recommend authors consider that the streaming widget will initially display the inline movie with a width of approximately 600 pixels, though the reader will also be able to view it at full screen. The recommended total size of a supplied movie is <15Mb. Best practice for providing movie files is to process them before submission using the Handbrake application and the following settings, or similar functionality with the ffmpeg software (see also Tips below):

Preset
Select the General=>”Fast720p30″ preset then modify it with the following manual settings.
Framerate (FPS)
30 + Constant Framerate
Quality
Constant Quality w/ RF=18-22 or Average bitrate 3000 kbps or greater
Picture
Anamorphic => Off
Other
Check: Web Optimized

A list of published articles with videos (>3000) in the AAS Journals can be found using our Astronomy Image Explorer by toggling the “Content Type => Videos” search facet on the left hand side.

Interactive Figures

Interactive figures give the reader the ability to manipulate the information contained in an image, which can add clarity or help further the author’s narrative. These figures consist of two parts, the static figure file for the LaTeX/PDF copy and a dynamic Javascript and HTML framework that provides interactive control. The basic requirements for these figures are:

javascript
The underlying javascript library should be well known and immutable.
data
The author should include the underlying dataset as a downloadable data file, which might include any of: csv, json, FITS, etc.
viewport
The current viewport limit for interactive graphics is 650 pixels. A wider HTML viewport will trigger a horizontal scroll for readers.

An example of an interactive figure is a 3D model. The underlying figure data is an X3D file while x3dom.js is the javascript driver that displays it. An author created interface is added via an HTML wrapper. The first 3D model published by the AAS Journals using this technique was Vogt et al. (2014). Vogt et al. have published a 2016 ApJ article entitled, “Advanced Data Visualization In Astrophysics: The X3D Pathway,” that more fully illustrates the power of X3D data objects and graphics.

Authors should consult online tutorials for more information on how to construct their own interactive figures. AAS Journal Data Editors can provide limited support via our ticket system. The current list of supported HTML/JS frameworks include:

Library Status Comments
x3dom x3dom.js fully supported
bokeh BokehJS experimental No server support

Authors mark up an interactive figure as they would any other figure in their manuscript file. You must supply a static representation of the interactive figure in EPS/PDF format encoded as a regular figure to serve as an reference for the reader. It is best practice for this static version to be a single “example” screenshot from the interactive figure.

The caption of an interactive figure should include text describing the interactivity and indicating that it is available in the HTML version of the final article. For instance, text such as “This figure is available online as an interactive figure” should be followed with a short description of the interaction itself — what exactly is displayed, colors, controls, annotations, etc. This explicit description is critical for readers for whom the interactive figure is inaccessible either due to a disability or web access.

Please submit all interactive figure materials in a single ZIP archive, e.g., fig03int.zip. The AAS Journal data editors will place your graphic on a webserver for testing before transfering it to IOP publishing for final insertion into your manuscript. Alternatively, include a URL link in your submission metadata to a hosted version of your graphic.

For reference purposes, a list of published articles with interactive in the AAS Journals can be found using our Astronomy Image Explorer by toggling the “Content Type => Interactive Figures” search facet.

Software Specific Advice

ffmpeg

ffmpeg is a powerful and sometimes overwhelmingly complicated piece of software for editing movies. At the AAS Journals we use this software to do things like switch codecs for animations, up the frame rate of an animation by duplicating frames, and merge multiple time-synchronized movies into single animations that fit into the final Journal article. Some examples of our use of ffmpeg are given here:

  • Given a large, low framerate MPEG-1 encoded file, change codecs, resample to 30 fps, and set CRF compression to 18

    • ffmpeg -i figure1.mpg -c:v libx264 -pix_fmt yuv420p -r 30 -crf 18 fig1anim.mp4
  • merge two different AIA observations of the same UT and clock duration into a single horizontally oriented animation that fits nicely on the final Journal webpage
    • ffmpeg -i AIA94.mpg -i HMI.mpg -filter_complex hstack \ 
      -c:v libx264 -pix_fmt yuv420p -r 30 -crf 18 fig1anim.mp4

Postscript

Not all PostScript (PS) are Encapsulated PostScript (EPS) files; in particular, an EPS file must contain a bounding box. Incorrectly constructed EPS files can cause problems when trying to combine the text with all the figures into one single PS file. Check the documentation for your graphics software to ensure that it does genuinely output compliant EPS files, and, in particular, please note that a PS file created by printing to file from the Windows or Macintosh operating systems will probably create a problematic PS file.

R

The R statistical software environment (http://www.r-project.org) has extensive publication-quality graphics capabilities. A common procedure uses the plot function followed by the dev.copy2eps function to deposit the graphic onto the disk in EPS format. Usage of plot is illustrated by the following: plot(x, y, pch=20, cex=0.6, col='crimson') where pch defines symbol shape, cex defines symbol size, and color names are given at http://cloford.com/resources/colours/500col.htm. Unsaturated colors, useful when points overlap, are specified like col='B0171F20', but needs be indirectly converted to EPS through the PDF format. R also incorporates the ggplot2, lattice, rgl, and other graphics systems, as well as a variety of image, 3-dimensional visualization, and animation capabilities.

Recommended Resources:

Other

When using SuperMongo (or any varieties of the Mongo program), a small bold font should be used for axis labels, lettering, etc., rather than the default “outline” font. The lines that make up the outline font are very thin and may drop out during the publication process.

IDL

Python