I have been currently working on determining the observable properties of the host galaxies of high redshift supernovae.  This project involves making some deep images of the galaxies.  Here are the host galaxies of 9 high redshift supernova events in the red and infrared, as seen by HST.

    I have labeled the images with the rest frame apparent U, B, or V magnitudes of the most likely host, depending on the band observed and the measured supernova redshift.  The R and I magnitudes were converted to rest frame Johnson U, B, and V magnitudes.  Since R and I correspond to B and V at z = 0.5, this conversion required little more than correcting for the (1+z) stretching of the wavelength region by subtracting 2.5 * log(1+z) from the observed magnitude.  m_B = 0 corresponds to a flux of 6.31e-9 photons per second, while m_V =  0 and m_U = 0 both correspond to 3.63e-9 photons per second.

    I also give absolute magnitudes for the objects where the distance modulus to the supernova has been determined.  The bolometric magnitude was obtained using a standard bolometric correction to m_V and applying the distance modulus.

    Below each set of images is a scale bar describing the size of an object 5" long at the redshift of the supernova, assuming a flat universe where Omega_lamba = 0.7 and Omega_matter = 0.3.

    Here the host galaxy is obvious.  It is a bright, face on, large spiral, with a large bulge and one very prominent arm.  The supernova is located in the  arm, only 4700 pc from the galaxy center.  The field looks typical of other fields of this depth: scattered with galaxies and containing very few stars.  It is strange that this, the most obvious spiral of all the hosts, is the reddest of the hosts.  Possibly, this galaxy has a higher metallicity than the others.

    This is the highest redshift supernova of the bunch.  The host galaxy is not obvious.  There is a star near the supernova (4" away), and there are two close-by (<10" away) galaxies of appropriate brightness to be at z = 0.97. The nearest galaxy center is at 57 kpc.  Either this event occurred far out in the halo of the galaxy, or the host is an LSB dwarf that is below our detection limits.  The field of this galaxy is similar to that of SN97a1.

    This host is very obvious, as the supernova occurred only 2400 pc from the galaxy center.  This is a more complex host.  It appears to be an ongoing merger of two galaxies.  The smaller of the two is developing a sizable tidal tail.  Possibly the supernova is a result of star formation which was induced by the interactions of the merging galaxies.  There is a very bright star in the field, but the surrounding galaxy population is again similar to the other fields.

    Here's another obvious spiral host.  This one is a bit inclined, and has two obvious, and bright spiral arms.  The supernova is located in one of the arms; only 3200 pc from the galaxy center.  The field here is a bit more sparse than the other fields in the sample.

    This host, centered only 1800 pc from the supernova, is an isolated irregular galaxy with a bright nucleus.  It appears to be part of an active group.  There is a possible merger 6.5" from this host and several galaxies within 10".  There are also many foreground spirals in this field.

This very complex host is an ongoing merger of at least two galaxies, but the supernova is 16.6 kpc from the merging nucleus, outside the unstructured, moderate surface brightness region.  There is also a foreground star near the galaxy, and another complicated merger occurring just 10" from the host.  The rest of the field contains about the same amount of galaxies as the other fields.

    The nearest galaxy to this rather isolated supernova, is a faint dwarf 13 kpc from the event.  The second closest galaxy is a bright, edge-on spiral, probably closer than z = 0.83.  If the spiral is at z = 0.83 then this event occurred at least 40 kpc from the galaxy center, out in the halo.  The field is a bit sparse , containing no stars and fewer galaxies than the other fields, possibly due to the long wavelength of the band.

    The only galaxy within 10" of this supernova looks like a barred dwarf irregular at 13.4 kpc from the event.  The similarity of this possible host to the possible host of 98e is amazing, though this event is at half the redshift of 98e.  Unlike 98e, the  immediate vicinity of the supernova is nearly devoid of galaxies, and the field in general is quite sparse.

    This supernova is only 7 kpc from the center of its rather amorphoushost.  The host looks like a face-on disk lacking a bulge.  The host has a couple of nearby neighbors.  One compact galaxy 1.5" away and a disky (possibly tidally disturbed) dwarf galaxy 2.8" away. This field in general is fairly sparse.  The supernova is in a more densely populated region of the field.