Juan P. Madrid

Structural Parameters of the M87 Globular Clusters (2009)

Madrid, Juan P., Harris, William E., Blakeslee, John P., Gomez, Matias

We derive structural parameters for ~2000 globular clusters in the giant Virgo elliptical M87 using extremely deep Hubble Space Telescope images in F606W (V) and F814W (I) taken with the ACS/WFC. The...

The Color-Magnitude Relation for Metal-Poor Globular Clusters in M87: Confirmation From Deep HST/ACS Imaging (2009)

Peng, Eric W., Jordan, Andres, Blakeslee, John P., Mieske, Steffen, Cote, Patrick, Ferrarese, Laura, ...

Metal-poor globular clusters (GCs) are our local link to the earliest epochs of star formation and galaxy building. Studies of extragalactic GC systems using deep, high-quality imaging have revealed...

Hubble Space Telescope observations of an extraordinary flare in the M87 jet (2009)

Madrid, Juan P.

HST-1, a knot along the M87 jet located 0.85 arcsec from the nucleus of the galaxy has experienced dramatic and unexpected flaring activity since early 2000. We present analysis of Hubble Space...

High-Impact Astronomical Observatories (2009)

Madrid, Juan P., Macchetto, Duccio

We derive the ranking of the astronomical observatories with the highest impact in astronomy based on the citation analysis of papers published in 2006. We also present a description of the...

Discovery of thirteen novae candidates in M87 (2006)

Madrid, Juan P., Sparks, William B., Ferguson, Henry C., Livio, Mario, Macchetto, Duccio

We have made thirteen positive identifications of near-ultraviolet (NUV) transient sources in the giant elliptical galaxy M87 using the Space Telescope Imaging Spectrograph (STIS) on board the Hubble...

Hubble Space Telescope Near-Infrared Snapshot Survey of 3CR radio source counterparts at low redshift (2006)

Madrid, Juan P., Chiaberge, Marco, Floyd, David, Sparks, William B., Macchetto, Duccio, Miley, George K., ...

We present newly acquired images of the near-infrared counterpart of 3CR radio sources. All the sources were selected to have a redshift of less than 0.3 to allow us to obtain the highest spatial...

The Warped Nuclear Disk of Radio Galaxy 3C 449 (2005)

Tremblay, Grant R., Quillen, Alice C., Floyd, David J. E., Noel-Storr, Jacob, Baum, Stefi A., Axon, David, ...

Among radio galaxies containing nuclear dust disks, the bipolar jet axis is generally observed to be perpendicular to the disk major axis. The FR I radio source 3C 449 is an outlier to this...

Hubble Space Telescope Science Metrics (2004)

Meylan, Georges, Madrid, Juan P., Macchetto, Duccio

Since its launch in April 1990, the Hubble Space Telescope (HST) has produced an increasing flow of scientific results. The large number of refereed publications based on HST data allows a detailed...