Graphics
Below are a few animations and figures I have made. Feel free to use
them for your own scientific presentations, with an appropriate
credit. The gif animations were made using gifsicle.
Animations

Animation showing the evolution of a SN Ia spectrum with age (in days
from maximum light). The right panel shows the corresponding Bband
light curve. The spectra have been normalized to the maximum flux
value. Based on the corresponding Nugent
templates.


Animation illustrating the difficulty of observing SN Ia at high
redshifts. The red portions highlight the two characteristic Si II
features at ~4000 and ~6150 Angstroms.


Animation showing the evolution of a supernova line profile with
age.
The left panel shows measured blueshifts of the Si II line at
~6150 Angstroms in SN Ia spectra as a function of age (in days from
maximum light), in units of 1000 km/s.
The upperright panel shows a schematic of a supernova atmosphere,
with color contours of constant lineofsight velocity, circular
isodensity contours (in steps of log base 5), and expansion velocity
vectors.
The lowerright panel shows the corresponding PCygni profile. The
vertical dotted line shows the locus of maximum absorption.


Animation showing the mean evolution of SN Ia spectra between 14 and
+25 days from maximum light.
Upper panel:
Standard (grey) and maximum (blue) deviation from the mean SN Ia
spectrum.
Lower panel:
Standard (grey) and maximum (blue) fractional residuals from the mean
SN Ia spectrum. The time and wavelength variations are real!

Figures

Bolometric light curves of Type Ia supernovae, illustrating the
range in peak luminosity and lightcurve morphology. Data courtesy of Max Stritzinger. [Also in postscript]


Upper panel:
SN Ia likelihood distribution for Omega_Lambda vs.
Omega_Matter. The red (green,blue) ellipses correspond to the 1 sigma
(2 sigma,3 sigma) contours. The input data are from
Tonry et al (2003) and include only SN Ia within the Hubble flow
( z < 0.01) that are not highly extinguished (A_V <
0.5 mag). There is a clear degeneracy along 0.8 Omega_Lambda 
0.6 Omega_Matter, and the flat universe
model (Omega_Lambda + Omega_Matter = 1, red line) does not lie within
the 1 sigma (68% probability) contour. The grey contours correspond to the
dynamical age of the universe, H_0 t_0. The SN Ia data favour
H_0 t_0 = [0.9,1.0].
Middle panel:
The three most distant SN Ia (z > 1) have been removed.
Lower panel:
Only SN Ia in the range 0.2 ≤ z ≤ 0.8 have been included,
illustrating the vital importance of the nearby sample.


Cartoon illustrating the density/velocity structure in SN Ia
envelopes and subsequent lineprofile morphology.
Upper panel:
Velocity contours (color coded) in units of the photospheric
velocity, vphot, in the (z,p) plane. Overplotted (black circles)
are logarithmic (base 5) density contours corresponding to a density
exponent n = 7. Also shown are velocity vectors corresponding to a
homologous velocity field (v(r) propto r). The black disk is the
photodisk of the supernova. The observer is located at
(z,p) = (infty,0), and hence the ``occulted region'' corresponds to
1 ≤ p ≤ 1 and z > 0.
Lower panel:
Synthetic line
profile flux (per unit frequency, F_nu), normalized to the
continuum flux F_cont, corresponding to the configuration
above and computed using the parametrized code SYNOW
(Fisher et al 1999). The abscissa is now the projected
velocity, along (p = 0), v_p. In this model, the peak of
emission is not shifted with respect to the rest wavelength (vpeak
= 0), and the location of maximum absorption is blueshifted by an
amount corresponding to the photospheric velocity (vabs =
vphot).
[Also in postscript]


Comparison of PCygni profiles of the resonance lines C IV λ1548
and Si II λ6347 in CMFGEN models of a nitrogenrich WolfRayet (WR)
star and a Type Ia supernova, respectively.
Lower panels:
Grayscale image of the quantity p I(p) as a function of p /
p_lim and classical Doppler
velocity v = [(λ/λ_0)  1]c, where p is the impact
parameter and I(p) the specific intensity along p (at
v). λ_0 is the rest wavelength
of the transition and c is the speed of light in
vacuum. p_lim corresponds to the impact parameter where p
I(p) = 0 for p > p_lim. For the SN Ia model, p_lim =
2.85 R_0, where
R_0 is the base radius of the CMFGEN radial grid where the continuum
optical depth tau_cont ~ 50  a photosphere thus exists
in this model configuration, corresponding here to a velocity of
9550 km/s. For the WR model, p_lim = 6.8 R_0, where R_0 is the
hydrostatic radius of the WR star. The terminal velocity of this model
is v_infty = 2000 km/s.
Upper panels:
Lineprofile flux obtained by summing p I(p) over the
range of p. The profiles have been normalized to the continuum
flux, F_cont.
[Also in postscript]


Observed and synthetic spectra of SN 1994D at 1 d from Bband
maximum.
Upper panel:
Comparison between the observed (black
line) and synthetic (solid red line) spectra of SN 1994D, computed
using the parametrized SYNOW code (Fisher et al 1999) using the
same input parameters as Branch et al (2005). The red dotted line
shows the effect of adding a highvelocity shell of Ca II in the SYNOW
model. The location of the Aband atmospheric absorption feature is
indicated with a telluric symbol.
Lower panel:
Synthetic line spectra for the individual
ions used in the SYNOW model, normalized to the continuum synthetic
flux (assumed to be a blackbody in SYNOW), in decreasing order of
atomic weight (from top to bottom).
[Also in postscript]


An observed supernova spectrum (in red) and the various individual
components (most of which nonsupernova!) with which observers have to
deal with.
[Also in postscript]
