The WMAP survey has been updated to use the 7 year integrated datasets from the HEASARC/Lambda archive. Previously we had been using the 5 year data. While there are small changes in the pixel values the underlying organization of the surveys is unchanged. All six WMAP surveys (5 colors and the galaxy subtracted image) have been updated.
If you would like to use the older 5 year datasets within SkyView please let us know.
Due to issues that affected several local systems the SkyView name resolvers were unavailable for 2 days and the SkyView Blog was offline for 10 days. Currently all SkyView services are back online. We apologize for the inconvenience.
To ensure the stability of the SkyView Blog we plan to perform additional maintenance sometime next week. Downtime will be required but should last less than 15 minutes. We appreciate your continued patience.
SkyView experienced two separate outages the last two days. 2MASS data were unavailable most of Tuesday due to the downtime of the remote system hosting the 2MASS survey data. The problems were resolved and 2MASS data are now available again in SkyView.
We also experienced image generation problems due to heavy usage that caused our temporary storage space to be depleted. We have tweaked the processes that clean out this area. As a result FITS files and specifically large ones will not be stored as long as they have been in the past. We will monitor the storage area to see if we can make the files available for a longer period of time and will look into possibly creating a larger storage area.
The operational SkyView machines have been moved to a virtualized environment. The numeric IP address for SkyView has been changed to 129.164.179.52. This actually points to a load balancer on top of several virtual machines. The new machines are already being used inside Goddard, and the change should propagate throughout the rest of the web over the next day or so as domain name servers refresh their caches. The address skys.gsfc.nasa.gov points to the same location.
So far there have been no problems reported in the transition. All surveys and services, including the SkyMorph NEAT archive and VO access should be available. Please let us know if you notice any anomalies.
SkyView will be unavailable for a limited time Tuesday (August 3, 2010) morning as we perform a hardware upgrade. We hope that the downtime will be short but it is possible that some remote survey data and SkyView services may not be immediately available after the upgrade. We will do our best to get everything back online as soon as possible. We apologize for the inconvenience.
A set of beautiful images mostly using RGB overlays from the DSS surveys has been put up at in a SkyView Flickr group. Flickr allows comments and tags on images. Perhaps Flickr is where the SkyView image gallery should go?
This morning we ran into a problem where too many SkyView requests were running simultaneously and so we had to reject some image requests. One of the reasons this happens is that SkyView accesses some data from remote services using the Virtual Observatory Simple Image Access (SIA) protocol. If those services are unavailable our requests can hang and build up on the system. Today we implemented a timeout for such requests of 15 seconds. There is also a new option, SIATimeout, that can be set when using the SkyView JAR file.
The final disk that appears to need repair is being worked on today. We have had to relocate the cache directories so queries that require access to remote systems (ie., FIRST, SDSS, Galex, 2MASS) will be slower as we re-transfer data. The SkyView Image Gallery is back online. Hopefully all recovery efforts will be complete within 24 hours. We thank you for your patience.
One of the constituent disks on a SkyView RAID system failed Monday evening. The disks are supposed to recover automatically from such a failure, but manifestly they did not and our operations personnel had to initiate recovery manually. Recovery activities were initiated in the background which allowed SkyView queries to resume although at a slower rate. A new problem cropped up Wednesday morning that resulted in one of the disks used to store generated images to become READ only. This caused some down time as we scrambled to rearrange disk space. Query processing has resumed once again but the SkyView Image Gallery (both image submission and gallery viewing) is offline until the file system check is completed.
We sincerely apologize for any inconvenience you may have encountered.
We are pleased to be able to announce the availability of a new medium resolution optical survey created by Axel Mellinger. This three color all-sky survey provides beautiful large-scale true-color images of the sky. For regions less than 30 degrees, the resolution is about 0.01 degrees. For larger regions the data is sampled from 0.1 degree pixels. For more information on these data check out the survey web site.
This survey provides an excellent complement to medium and low resolution surveys in other wavelengths, e.g., IRAS/IRIS and RASS and the new Fermi gamma-ray surveys that we plan on introducing in the next few weeks.
All-Sky Aitoff Projection of Mellinger data
Many thanks to Dr. Mellinger for allowing us to include these data in SkyView.
The image above was created using the following arguments.
survey=mell-r,mell-g,mell-b
quicklook=jpeg
rgb=true
projection=Ait
size=360,180
pixels=1000,500
sampler=Clip
The Mellinger survey is only available through the SkyView web site and cannot be retrieved using a local copy of the Jar file. The survey sets some defaults differently from other surveys. The default scaling is linear and the min and max values are set to 0 and 255 to preserve a consistent scaling regardless of the region you happen to pick out. We also set the ClipIntensive keyword when the Clipping sampler to preserve the scaling.