Standard Candle Method Research Articles

Distance estimate and progenitor characteristics of SN 2005cs in M51

Distance to the Whirlpool Galaxy (M51, NGC 5194) is estimated using published photometry and spectroscopy of the Type II-P supernova SN 2005cs. Both the Expanding Photosphere Method (EPM) and the Standard Candle Method (SCM), suitable for SNe II-P, were applied. The average distance (7.1 \pm 1.2 Mpc) is in good agreement with earlier SBF- and PNLF-based distances, but slightly longer than the distance obtained by Baron et al. for SN 1994I via the Spectral Fitting Expanding Atmosphere Method (SEAM). Since SN 2005cs exhibited low expansion velocity during the plateau phase, similarly to SN 1999br, the constants of SCM were re-calibrated including the data of SN 2005cs as well. The new relation is better constrained in the low velocity regime (v_{ph}(50) ~ 1500 - 2000$ km/s), that may result in better distance estimates for such SNe. The physical parameters of SN 2005cs and its progenitor are re-evaluated based on the updated distance. All the available data support the low-mass (~ 9 M_\odot) progenitor scenario proposed previously by its direct detection with the Hubble Space Telescope.

SN 2004A: another Type II-P supernova with a red supergiant progenitor

We present a monitoring study of SN 2004A and probable discovery of a progenitor star in pre-explosion Hubble Space Telescope (HST) images. The photometric and spectroscopic monitoring of SN 2004A show that it was a normal Type II-P which was discovered in NGC 6207 about two weeks after explosion. We compare SN 2004A to the similar Type II-P SN 1999em and estimate an explosion epoch of 2004 January 6. We also calculate three new distances to NGC 6207 of 21.0 ± 4.3,-21.4 ± 3.5 and 25.1 ± 1.7-Mpc. The former was calculated using the Standard Candle Method (SCM) for SNe-II-P, and the latter two from the brightest supergiants method (BSM). We combine these three distances with existing kinematic distances, to derive a mean value of 20.3 ± 3.4-Mpc. Using this distance, we estimate that the ejected nickel mass in the explosion is 0.046+0.031−0.017-M⊙. The progenitor of SN 2004A is identified in pre-explosion WFPC2 F814W images with a magnitude of mF814W= 24.3 ± 0.3, but is below the detection limit of the F606W images. We show that this was likely a red supergiant (RSG) with a mass of 9+3−2-M⊙. The object is detected at 4.7σ above the background noise. Even if this detection is spurious, the 5σ upper limit would give a robust upper mass limit of 12-M⊙ for a RSG progenitor. These initial masses are very similar to those of two previously identified RSG progenitors of the Type II-P SNe 2004gd (8+4−2-M⊙) and 2005cs (9+3−2-M⊙).

The first year of SN 2004dj in NGC 2403★

New BV RI photometry and optical spectroscopy of the Type IIp supernova 2004dj in NGC 2403, obtained during the first year since discovery, are presented. The progenitor cluster, Sandage 96, is also detected on pre-explosion frames. The light curve indicates that the explosion occurred about 30 d before discovery, and the plateau phase lasted about +110 ± 20 d after that. The plateau-phase spectra have been modelled with the synow spectral synthesis code using H, Na i, Ti ii, Sc ii, Fe ii and Ba i lines. The SN distance is inferred from the expanding photosphere method and the standard candle method applicable for SNe IIp. They resulted in distances that are consistent with each other as well as earlier Cepheid and Tully–Fisher distances. The average distance, D= 3.47 ± 0.29 Mpc is proposed for SN 2004dj and NGC 2403. The nickel mass produced by the explosion is estimated as ∼0.02 ± 0.01 M⊙. The spectral energy distribution of the progenitor cluster is reanalysed by fitting population synthesis models to our observed BV RI data supplemented by U and JHK magnitudes from the literature. The χ2 minimization revealed a possible ‘young’ solution with cluster age Tcl= 8 Myr, and an ‘old’ solution with Tcl= 20–30 Myr. The ‘young’ solution would imply a progenitor mass M > 20 M⊙, which is higher than the previously detected progenitor masses for Type II SNe.

A study of the Type II-P supernova 2003gd in M74

We present photometric and spectroscopic data of the type II-P supernova 2003gd, which was discovered in M74 close to the end of its plateau phase. SN 2003gd is the first type II supernova to have a directly confirmed red supergiant progenitor. We compare SN 2003gd with SN 1999em, a similar type II-P supernova, and estimate an explosion date of 18th March 2003. We determine a reddening towards the supernova of E(B-V) = 0.14+/-0.06, using three different methods. We also calculate three new distances to M74 of 9.6+/-2.8 Mpc, 7.7+/-1.7 Mpc and 9.6+/-2.2 Mpc. The former was estimated using the Standardised Candle Method (SCM), for type II supernovae, and the latter two using the Brightest Supergiants Method (BSM). When combined with existing kinematic and BSM distance estimates, we derive a mean value of 9.3+/-1.8 Mpc. SN 2003gd was found to have a lower tail luminosity compared to other ``normal'' type II-P SNe bringing into question the nature of this supernova. We present a discussion concluding that this is a ``normal'' type II-P supernova which is consistent with the observed progenitor mass of 8(+4/-2) Mo.

The Standard Candle Method for Type II Supernovae and the Hubble Constant

SummaryThe “standard candle method” for Type II plateau supernovae produces a Hubble diagram with a dispersion of 0.3 mag, which implies that this technique can produce distances with a precision of 15%. Using four nearby supernovae with Cepheid distances I find H0(V)=75±7, and H0(I)=65±12.

The Cepheid Distance to NGC 1637: A Direct Test of the Expanding Photosphere Method Distance to SN 1999em

Type II-plateau supernovae (SNe II-P) are the classic variety of core-collapse events that result from isolated, massive stars with thick hydrogen envelopes intact at the time of explosion. Their distances are now routinely estimated through two techniques: the expanding photosphere method (EPM), a primary distance-determining method, and the recently developed standard-candle method (SCM), a promising secondary technique. Using Cycle 10 Hubble Space Telescope (HST) observations, we identify 41 Cepheid variable stars in NGC 1637, the host galaxy of the most thoroughly studied SN II-P to date, SN 1999em. Remarkably, the Cepheid distance that we derive to NGC 1637, D = 11.7 ± 1.0 Mpc, is nearly 50% larger than earlier EPM distance estimates to SN 1999em. This is the first direct comparison between these two primary distance-determining methods for a galaxy hosting a well-observed, spectroscopically and photometrically normal, SN II-P. Extensive consistency checks show strong evidence to support the Cepheid distance scale, so we are led to believe either that SN 1999em is in some heretofore unsuspected way an unusual SN II-P, or that the SN II-P distance scale must be revised. Assuming the latter, this one calibration yields H0(EPM) = 57 ± 15 km s-1 Mpc-1 and H0(SCM) = 59 ± 11 km s-1 Mpc-1; additional calibrating galaxies are clearly desirable in order to test the robustness of both determinations of H0. The HST observations of NGC 1637 also captured the fading SN 1999em 2 yr after explosion, providing the latest photometry ever obtained for an SN II-P. The nebular-phase photometric behavior of SN 1999em closely follows that observed for SN 1987A at similar epochs. The V and I light curves are both declining at rates significantly greater than the decay slope of 56Co predicts. This is likely due to an increasing transparency of the envelope to gamma rays and perhaps also to the formation of dust in the cooling atmosphere of the SN. The absolute V-band brightness of SN 1999em is ~0.25 mag brighter than SN 1987A at the same epochs, which suggests that a slightly greater amount of radioactive 56Ni, ~0.09 M☉, was ejected by SN 1999em than was derived for SN 1987A (0.075 M☉).

Planetary nebulae as standard candles. I - Evolutionary models

view Abstract Citations (229) References (52) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Planetary Nebulae as Standard Candles. I. Evolutionary Models Jacoby, George H. Abstract We use a series of models of evolving planetary nebulae to derive their time-dependent luminosity history for a selection of central star masses. We then simulate observations of ensembles of planetary nebulae (PNs) using Monte Carlo methods to derive theoretical luminosity functions. The generated [O III] λ5007 luminosity functions agree very well with observations of M31, M81, and Leo Group (NGC 3377, NGC 3379, NGC 3384) galaxies, exhibiting a sharp cutoff over 0.8 mag at the bright end. This cutoff strongly implies that the distribution of central star masses for bright PNs is centered near 0.61 M_sun_ and has a narrow high-side Gaussian width (σ) near 0.02 M_sun_. The Hβ luminosity function also exhibits a bright cutoff, but at a flux level 1.7 mag fainter than the [O III] luminosity function. We propose deriving extragalactic distances by comparing the shapes of the luminosity functions of PNs in distant galaxies with those found for nearby reference galaxies. The simpler, but less accurate, standard candle method, whereby one simply compares the luminosities of the brightest PN(s) in a galaxy to the brightest PNs in reference galaxies such as those in the Local Group can also be used to obtain distances. Publication: The Astrophysical Journal Pub Date: April 1989 DOI: 10.1086/167274 Bibcode: 1989ApJ...339...39J Keywords: Astronomical Models; Evolution (Development); Galaxies; Luminosity; Planetary Nebulae; Electron Energy; Emission Spectra; H Beta Line; Mass Distribution; Standards; Stellar Mass; Time Dependence; Astrophysics; GALAXIES: DISTANCES; LUMINOSITY FUNCTION; NEBULAE: PLANETARY full text sources ADS | data products SIMBAD (7) NED (5) Related Materials (10) Part 2: 1989ApJ...339...53C Part 3: 1989ApJ...344..704J Part 4: 1989ApJ...344..715C Part 5: 1990ApJ...356..332J Part 6: 1990ApJ...365..471J Part 7: 1991ApJ...383..487C Part 8: 1992ApJ...388..268C Part 9: 1993ApJ...416...62M Part 10: 1996ApJ...462....1J Part 11: 1997ApJ...479..231F