Hera -- Astronomical Data Analysis over the Internet
Hera is the new data processing facility
provided by the HEASARC at the NASA Goddard Space Flight Center
astronomical data files. Hera provides all the preinstalled software packages,
local disk space, and computing resources needed to do general processing of
data files residing on the user's local computer,
and to do advanced research using the publicly available data from
High Energy Astrophysics
Qualified students, educators, and
may freely use
the Hera services over the internet for research and educational purposes.
The Hera computer hardware includes
a cluster of Linux workstations to do the data analysis
- local disk space for temporary storage of user's data and results.
high speed access to the terabytes of data in the
HEASARC's high energy astrophysics
The Hera software includes
general utility programs
for processing and manipulating any
FITS image or table, as well as hundreds of
more specialized programs
for analyzing data from high-energy astrophysics missions
such as ROSAT, Chandra, XMM-Newton, Swift, and Suzaku.
The Different Flavors of Hera
Several distinctly different user-interfaces to the underlying Hera services
are currently available to meet different needs.
These 4 different user interfaces are described in more detail
in the following paragraphs.
run majority of programs in the FTOOLS software suite from a browser
without the need to download and to install FTOOLS software.
run individual tasks from a
command line window on your desktop to analyze local FITS data files
(just as if the software were installed
on your local machine), or
use a graphical user interface to control the execution
of different software tasks
and manage your files on both the Hera server and on your local machine, or
select any data set in the HEASARC data archive using your
web browser, and then click on the associated 'Hera' link to instantly
start analyzing that particular data set.
- This is a command-line interface
to Hera that allows you to run any of the
software tasks that are installed on the Hera servers to analyze
data files that reside on your local computer.
You execute each task the same way as you would if the software packages were
installed on your local machine, by specifying the name of
the task on the command
line, followed by the values of any other task parameters.
The only difference is that that you must
preface the entire command with the string "fv -r".
interface then transparently copies the input data files to a
temporary disk area on the Hera server, runs the
task, and then copies any output text and data back to your local
computer. If the task is expected to take a while to run, you may
optionally request that Hera send an email notification when the
task has completed, at which point you may reconnect to Hera and
download the results.
- This is the graphical Hera interface that provides
interactive access to all the Hera capabilities.
First time users can create a new Hera ID and password to connect
to the system. You can then use the
Hera GUI to analyze the data files on your local machine or in
your private disk area on the Hera servers.
You may transfer data files between your Hera disk area and your local
computer using your mouse to 'drag and drop' the files from one
machine to the other.
You may select additional data sets from
the HEASARC's high energy astrophysics archive using the
Browse web interface
and save them to your Hera disk area for further analysis (no need to
download the data to your local computer first).
The data files on the Hera disk area are preserved between
sessions so you may exit from Hera
and then return at a later date to continue the analysis.
(Policies for managing the Hera disk space and deleting
unused data and accounts are currently under development).
- This version of Hera lets you instantly analyze a single data set from the HEASARC
data archive. You simply use the
Browse web interface
to locate a data set of interest, and then click on the
'H' Hera services link that is shown next to that data set.
All the data products associated with that particular
observation are copied to a new temporary Hera session,
and then the same
as is used in the Standard Hera interface
will start up allowing you to further examine and analyze the data.
The main difference from the Standard Hera interface
is that the data files in the Anonymous Hera session
are deleted when the session ends, however
before doing so, you are given the opportunity to copy
the data to a new or existing Standard Hera account, or download
the data to your local computer.
Web Hera (Under Development) - This is the Hera web portal to FTOOLS software. By using Web Hera, the user will not need to download or to install the HEASoft suite locally. Users can perform data analysis with HEASoft using their web browser as the software interface.
Getting Started with Hera
To learn how to effectively use Hera as quickly as possible, we
recommend that you follow the steps on the
Getting Started web page.
Also refer to the
frequently asked questions page.
Software and Hardware Requirements for Using Hera
Users may connect to Hera from most commonly used
computers systems, including Unix/linux workstations and Mac OS-X PCs.
Many of the Hera services can be accessed from Windows PCs as well.
The only requirements for using Hera are:
Fv FITS file viewer and editor
must be installed on the local machine (version v4.4 or higher).
Fv serves as the
local client portal to the Hera services.
broadband access to the Internet
access to a standard web browser such as Firefox or
Important note concerning firewalls: Some Hera users have
experienced problems using Hera because the firewall system
on their local computer or network blocked the connection
to the Hera servers.
Network connections from
your local machine to the Hera servers must be allowed on certain
computer ports in order for Hera to function.
Please contact the Hera developers for advice if
you experience problems connecting to Hera.
Hera is an experimental project initially funded by a
NASA AISRP grant. We are interested in your suggestions and comments
on how Hera can be improved. Please send any comments using the 'Mail'
button in the lower right corner of the Hera GUI window, or email us
directly at this address: heradev "at" athena.gsfc.nasa.gov.
The Hera development team currently consists of:
Previous contributors include:
Ziqin Pan, Peter Wilson, Ning Gan, and Christina Heikkila