Scholar iON
Academic Synthesis
The collection of papers highlights the evolving landscape of astrophysical research dissemination and debates within the field. Metcalfe (2005) underscores the significant impact of the arXiv preprint server (astro-ph) in increasing citation rates, indicating its role as a primary resource for astronomers. Meanwhile, Reichart (2005) engages in a methodological debate with Guidorzi regarding the modeling of GRB variability-luminosity correlations, emphasizing the importance of accounting for sample variance in data fitting. Alam et al. (2004) defend their approach to modeling dark energy dynamics against criticism, illustrating ongoing discussions about the robustness of cosmological parameterizations. Lastly, Collar (1997) addresses critiques and inconsistencies in previous works, showcasing the iterative nature of scientific scrutiny and dialogue in astrophysics. This body of work collectively highlights the dynamic interplay between methodological rigor, data interpretation, and the evolving platforms for scholarly communication in astrophysics.
The rise in the use of the arXiv preprint server (astro-ph) over the past decade has led to a major shift in the way astronomical research is disseminated. Schwarz & Kennicutt (2004) recently found that Astrophysical Journal papers posted to astro-ph are cited roughly twice as often as papers that are not posted, suggesting that the preprint server has become the primary resource for many astronomers to keep up with the literature. I describe a simple method to determine the adoption rate and citation impact of astro-ph over time for any journal using NASA's Astrophysics Data System (ADS). I use the ADS to document the rise in the adoption of astro-ph for three major astronomy journals, and to conduct a broad survey of the citation impact of astro-ph in 13 different journals. I find that the factor of two boost in citations for astro-ph papers is a common feature across most of the major astronomy journals.
Guidorzi has now written two papers (astro-ph/0507588 and astro-ph/0508483, both accepted to MNRAS) on the GRB variability-luminosity correlation in which he finds that expanded samples of L vs. V data are not well described by a power law because the scatter of the data around such a model is more than can be accounted for by the data's statistical errors alone (sample variance) -- "in contrast with the original findings by Reichart et al. (2001)" -- but then proceeds to model these data with a power law anyway and finds significantly shallower L vs. V relationships than Reichart et al. (2001) found. However, as Reichart & Nysewander (2005; astro-ph/0508111) pointed out after Guidorzi's first posting but before his second, Reichart et al. (2001) never modeled their L vs. V data with a power law. Instead, they used a power law with a distribution around it to accommodate and measure this sample variance. Ignoring sample variance in a fit that requires it very easily results in incorrect fitted parameter values due to increased sensitivity to outliers, as well as significantly underestimated uncertainties in these fitted parameter values. Fitting to Guidorzi's own data, Reichart & Nysewander (2005) showed that when sample variance is included in the model, L ~ V^3.4(+0.9,-0.6) with a sample variance of sigma_logV = 0.20(+0.04,-0.04), which is in excellent agreement with the original finding of Reichart et al. (2001) -- L ~ V^3.3(+1.1,-0.9) with a sample variance of sigma_logV = 0.18(+0.07,-0.05) -- when the sample was approximately one-third its current size.
In a recent paper (astro-ph/0311364) Alam et al argued that the SNe data of Tonry et al 2003 and Barris et al 2003 appear to favour DE which evolves in time, provided no other priors are invoked. (The effect of invoking priors such as the age of the Universe, the values of $H_0$ and $Ξ©_m$ and CMB/LSS observations could modify this conclusion, as demonstrated in astro-ph/0403687 and other recent papers.) The approach adopted by Alam et al to reconstruct the properties of DE was severely (and, as we shall show below -- unfairly) criticized by JΓΆnsson et al in astro-ph/0404468. In this paper we re-examine the parametrisation used in astro-ph/0311364 and show that, contrary to the claims of JΓΆnsson et al, the results obtained from this reconstruction are robust and therefore representative of the true nature of dark energy.
A Reply to the criticisms contained in astro-ph/9612003 is provided and a logical inconsistency in astro-ph/9612214 is pointed out.
In an essay published in 1997, M. J. Harris pointed out that the development of a theoretical explanation, or "synthesis," of a group of astronomical results can lead to a situation where subsequent observations are forced to fit within that framework. Moreover, new results may be reported that fit within the framework but which can no longer be reproduced following the advent of more sensitive observations that overturn the synthesis. Although Harris considered gamma-ray line transients, a similar situation regarding the collapsar model for gamma-ray bursts now holds. In two recent papers posted on astro-ph by J. S. Bloom et al., and by P. A. Price et al., the synthesis effect is illustrated with respect to the collapsar model. These authors dismiss observations that contradict the collapsar model, appeal to "simplicity" to justify their preferred model, and dismiss (or better yet, ignore) competing models with unscientific reasoning. Whether or not the collapsar model is correct, these papers serve as textbook examples of the synthesis effect in science.
We point out that in Granato & Danese 1994 and Granato et al. 1997 we predicted maximum observable sizes for the putative torus in NGC1068 of 10-20 pc, not "hundreds of parsecs" as stated by M. Elitzur in astro-ph/0512025.
A short replay to the comment of Rossetti & Molendi (astro-ph/0702417) in answer to the paper of Fusco-Femiano, Landi & Orlandini 2007 regarding the presence of a nonthermal component in the Coma Cluster spectrum.
Following this astro-ph communication, we release a set of 10,000 WMAP ILC simulations, produced as described by Eriksen et al. (2004). We strongly encourage that an analysis of these simulations accompanies any scientific analysis of the observed ILC map, in order to assess the stability of the results. For examples of such analyses, we refer the reader to our original paper. In particular, Figure 1c) and d) show the bias and uncertainty induced by the ILC method, and Figure 7 shows a sobering examples of a low-l analysis; the reconstructed quadrupole-octopole alignment is plotted against the true input alignment, and the correlation is underwhelming. It can hardly be emphasized too strongly -- the heavily processed full-sky WMAP maps are not reliable for quantitative analysis, neither at large nor small scales, and they should only, at best, be used as supportive evidence. We hope that these simulations will reduce some of the confusion regarding these maps that currently exists in the community.
We briefly comment on a paper by Rubano and Scudellaro [astro-ph/0103335] where they found general exact solutions for two classes of exponential potentials in a scalar field model for quintessence. In that paper the authors were led to some interesting conclusions after a proper choice of the integration constants. By using dimensionless variables we show that the integration constants can be found explicitly without additional assumptions. In consequence we revise some results and conclusions in that paper. We also reproduce observations for Type-1a supernovae with good accuracy.
A contour plot of positive iso-J curves is shown for a gravitational binary lens epsilon_2 = 0.1883 and ell = 0.687. The caustic curve is made of 4-cusped central caustic (so-called "stealth bomber") on the lens axis and two triangular caustics off the lens axis. The cusps of the trioids are all negative cusps. The positive image magnification contours outside the positive cusps on the lens axis are elongated along the symmetry axis. It is in contrast with figure 4 of astro-ph/0206162 (Gaudi and Petters) where the contours appear to contract along the symmetry axis. We apologize if our citation of their figure 4 without the caution played any role of causing confusion with readers.