Person: Finkbeiner, Douglas
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Finkbeiner
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Douglas
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Finkbeiner, Douglas
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Publication A Galactic-scale gas wave in the solar neighbourhood(Springer Science and Business Media LLC, 2020-01-07) Alves, Joao; Zucker, Catherine; Goodman, Alyssa; Speagle, Joshua; Meingast, Stefan; Robitaille, Thomas; Finkbeiner, Douglas; Schlafly, Edward; Green, GregoryFor the past 150 years, the prevailing view of the local Interstellar Medium (ISM) was based on a peculiarity known as the Gould's Belt (Herschel 1847, Gould 1874, Bobylev 2014, Palous 2016), an expanding ring of young stars, gas, and dust, tilted about 20 deg to the Galactic plane. Still, the physical relation between local gas clouds has remained practically unknown because the distance accuracy to clouds is of the same order or larger than their sizes (Maddalena 1986, Lombardi 2008, Schlafly 2014). With the advent of large photometric surveys (Chambers 2016) and the Gaia satellite astrometric survey (Brown 2018) this situation has changed (Zucker 2019) Here we report the 3-D structure of all local cloud complexes. We find a narrow and coherent 2.7 kpc arrangement of dense gas in the Solar neighborhood that contains many of the clouds thought to be associated with the Gould Belt. This finding is inconsistent with the notion that these clouds are part of a ring, disputing the Gould Belt model. The new structure comprises the majority of nearby star-forming regions, has an aspect ratio of about 1:20, and contains about 3 million solar masses of gas. Remarkably, the new structure appears to be undulating and its 3-D distribution is well described by a damped sinusoidal wave on the plane of the Milky Way, with an average period of about 2 kpc and a maximum amplitude of about 160 pc. Our results represent a first step in the revision of the local gas distribution and Galactic structure and offer a new, broader context to studies on the transformation of molecular gas into stars.Publication The Pan-STARRS 1 Photometric Reference Ladder, Release 12.0(IOP Publishing, 2013) Magnier, E. A.; Schlafly, E.; Finkbeiner, Douglas; Juric, M.; Tonry, J. L.; Burgett, W. S.; Chambers, K. C.; Flewelling, H. A.; Kaiser, N.; Kudritzki, R.-P.; Morgan, J. S.; Price, P. A.; Sweeney, W. E.; Stubbs, ChristopherAs of 2012 Jan 21, the Pan-STARRS1 \(3\pi\) Survey has observed the 3/4 of the sky visible from Hawaii with a minimum of 2 and mean of 7.6 observations in 5 filters, \(g_{\rm P1},r_{\rm P1},i_{\rm P1},z_{\rm P1},y_{\rm P1}\). Now at the end of the second year of the mission, we are in a position to make an initial public release of a portion of this unprecedented dataset. This article describes the PS1 Photometric Ladder, Release 12.01 This is the first of a series of data releases to be generated as the survey coverage increases and the data analysis improves. The Photometric Ladder has rungs every hour in RA and at 4 intervals in declination. We will release updates with increased area coverage (more rungs) from the latest dataset until the PS1 survey and the final re-reduction are completed. The currently released catalog presents photometry of \(\sim 1000\) objects per square degree in the rungs of the ladder. Saturation occurs at \(g_{\rm P1}, r_{\rm P1}, i_{\rm P1} \sim 13.5; z_{\rm P1} \sim 13.0;\) and \(y_{\rm P1} \sim 12.0\). Photometry is provided for stars down to \(g_{\rm P1}, r_{\rm P1}, i_{\rm P1} \sim 19.1\) in the AB system. This data release depends on the rigid `Ubercal' photometric calibration using only the photometric nights, with systematic uncertainties of (8.0, 7.0, 9.0, 10.7, 12.4) millimags in \((g_{\rm P1},r_{\rm P1},i_{\rm P1},z_{\rm P1},y_{\rm P1})\). Areas covered only with lower quality nights are also included, and have been tied to the Ubercal solution via relative photometry; photometric accuracy of the non-photometric regions is lower and should be used with caution.Publication Supercal: Cross-Calibration of Multiple Photometric Systems to Improve Cosmological Measurements with Type Ia Supernovae(IOP Publishing, 2015) Scolnic, D.; Casertano, S.; Riess, A.; Rest, A.; Schlafly, E.; Foley, R. J.; Finkbeiner, Douglas; Tang, C.; Burgett, W. S.; Chambers, K. C.; Draper, P. W.; Flewelling, H.; Hodapp, K. W.; Huber, M. E.; Kaiser, N.; Kudritzki, R. P.; Magnier, E. A.; Metcalfe, N.; Stubbs, ChristopherCurrent cosmological analyses which use Type Ia supernova (SN Ia) observations combine SN samples to expand the redshift range beyond that of a single sample and increase the overall sample size. The inhomogeneous photometric calibration between different SN samples is one of the largest systematic uncertainties of the cosmological parameter estimation. To place these different samples on a single system, analyses currently use observations of a small sample of very bright flux standards on the HST system. We propose a complementary method, called ‘Supercal’, in which we use measurements of secondary standards in each system, compare these to measurements of the same stars in the Pan-STARRS1 (PS1) system, and determine offsets for each system relative to PS1, placing all SN observations on a single, consistent photometric system. PS1 has observed 3π of the sky and has a relative calibration of better than 5 mmag (for ∼ 15 < griz < 21 mag), making it an ideal reference system. We use this process to recalibrate optical observations taken by the following SN samples: PS1, SNLS, SDSS, CSP, and CfA1-4. We measure discrepancies on average of 10 mmag, but up to 35 mmag, in various optical passbands. We find that correcting for these differences changes recovered values for the dark energy equation-of-state parameter, w, by on average 2.6%. This change is roughly half the size of current statistical constraints on w. The size of this effect strongly depends on the error in the B − V calibration of the low-z surveys. The Supercal method will allow future analyses to tie past samples to the best calibrated sample.Publication Consistent scenarios for cosmic-ray excesses from Sommerfeld-enhanced dark matter annihilation(IOP Publishing, 2011) Finkbeiner, Douglas; Goodenough, Lisa; Slatyer, Tracy R; Vogelsberger, Mark; Weiner, NealAnomalies in direct and indirect detection have motivated models of dark matter consisting of a multiplet of nearly-degenerate states, coupled by a new GeV-scale interaction. We perform a careful analysis of the thermal freezeout of dark matter annihilation in such a scenario. We compute the range of "boost factors" arising from Sommerfeld enhancement in the local halo for models which produce the correct relic density, and show the effect of including constraints on the saturated enhancement from the cosmic microwave background (CMB). We find that boost factors from Sommerfeld enhancement of up to ~800 are possible in the local halo. When the CMB bounds on the saturated enhancement are applied, the maximal boost factor is reduced to ~400 for 1-2 TeV dark matter and sub-GeV force carriers, but remains large enough to explain the observed Fermi and PAMELA electronic signals. We describe regions in the DM mass-boost factor plane where the cosmic ray data is well fit for a range of final states, and show that Sommerfeld enhancement alone is enough to provide the large annihilation cross sections required to fit the data, although for light mediator masses (less than ~200 MeV) there is tension with the CMB constraints in the absence of astrophysical boost factors from substructure. Additionally, we consider the circumstances under which WIMPonium formation is relevant and find for heavy WIMPs (greater than ~2 TeV) and soft-spectrum annihilation channels it can be an important consideration; we find regions with dark matter mass greater than 2.8 TeV that are consistent with the CMB bounds and have ~600-700 present-day boost factors.Publication Is the 130 GeV line real? A search for systematics in the Fermi-LAT data(IOP Publishing, 2013) Finkbeiner, Douglas; Su, Meng; Weniger, ChristophOur recent claims of a Galactic center feature in Fermi-LAT data at approximately 130 GeV have prompted an avalanche of papers proposing explanations ranging from dark matter annihilation to exotic pulsar winds. Because of the importance of such interpretations for physics and astrophysics, a discovery will require not only additional data, but a thorough investigation of possible LAT systematics. While we do not have access to the details of each event reconstruction, we do have information about each event from the public event lists and spacecraft parameter files. These data allow us to search for suspicious trends that could indicate a spurious signal. We consider several hypotheses that might make an instrumental artifact more apparent at the Galactic center, and find them implausible. We also search for an instrumental signature in the Earth limb photons, which provide a smooth reference spectrum for null tests. We find no significant 130 GeV feature in the Earth limb sample. However, we do find a marginally significant 130 GeV feature in Earth limb photons with a limited range of detector incidence angles. This raises concerns about the 130 GeV Galactic center feature, even though we can think of no plausible model of instrumental behavior that connects the two. A modest amount of additional limb data would tell us if the limb feature is a statistical fluke. If the limb feature persists, it would raise doubts about the Pass 7 processing of E > 100 GeV events. At present we find no instrumental systematics that could plausibly explain the excess Galactic center emission at 130 GeV.Publication PAMELA, DAMA, INTEGRAL and signatures of metastable excited WIMPs(IOP Publishing, 2009) Finkbeiner, Douglas; Slatyer, Tracy R; Weiner, Neal; Yavin, ItayModels of dark matter with ~ GeV scale force mediators provide attractive explanations of many high energy anomalies, including PAMELA, ATIC, and the WMAP haze. At the same time, by exploiting the ~ MeV scale excited states that are automatically present in such theories, these models naturally explain the DAMA/LIBRA and INTEGRAL signals through the inelastic dark matter (iDM) and exciting dark matter (XDM) scenarios, respectively. Interestingly, with only weak kinetic mixing to hypercharge to mediate decays, the lifetime of excited states with delta < 2 m_e is longer than the age of the universe. The fractional relic abundance of these excited states depends on the temperature of kinetic decoupling, but can be appreciable. There could easily be other mechanisms for rapid decay, but the consequences of such long-lived states are intriguing. We find that CDMS constrains the fractional relic population of ~100 keV states to be <~ 10^-2, for a 1 TeV WIMP with sigma_n = 10^-40 cm^2. Upcoming searches at CDMS, as well as xenon, silicon, and argon targets, can push this limit significantly lower. We also consider the possibility that the DAMA excitation occurs from a metastable state into the XDM state, which decays via e+e- emission, which allows lighter states to explain the INTEGRAL signal due to the small kinetic energies required. Such models yield dramatic signals from down-scattering, with spectra peaking at high energies, sometimes as high as ~1 MeV, well outside the usual search windows. Such signals would be visible at future Ar and Si experiments, and may be visible at Ge and Xe experiments. We also consider other XDM models involving ~ 500 keV metastable states, and find they can allow lighter WIMPs to explain INTEGRAL as well.Publication Microwave emission from aligned dust(Elsevier BV, 2003) Lazarian, A; Finkbeiner, DouglasPolarized microwave emission from dust is an important foreground that may contaminate polarized CMB studies unless carefully accounted for. We discuss potential difficulties associated with this foreground, namely, the existence of different grain populations with very different emission/polarization properties and variations of the polarization yield with grain temperature. In particular, we discuss observational evidence in favor of rotational emission from tiny PAH particles with dipole moments, i.e. ``spinning dust'', and also consider magneto-dipole emission from strongly magnetized grains. We argue that in terms of polarization, the magneto-dipole emission may dominate even if its contribution to total emissivity is subdominant. Addressing polarized emission at frequencies larger than approsimately 100 GHz, we discuss the complications arising from the existence of dust components with different temperatures and possibly different alignment properties.Publication The Effect of FIR Emission from SDSS Galaxies on the SFD Galactic Extinction Map(Oxford University Press (OUP), 2007) Yahata, Kazuhiro; Yonehara, Atsunori; Suto, Yasushi; Turner, Edwin L.; Broadhurst, Tom; Finkbeiner, DouglasWe compare the most successful and widely used map of Galactic dust extinction, provided by Schlegel, Finkbeiner & Davis (1998; hereafter SFD), to the galaxy number counts in the Sloan Digital Sky Survey (SDSS) photometric/spectroscopic DR4 sample. We divide the SDSS survey area into 69 disjoint subregions according to the dust extinction provided by SFD and compare the surface number density of galaxies in each subregion. As expected, the galaxy surface number density decreases with increasing extinction but only for SFD extinction values above about 0.1 to 0.2 magnitudes (depending on the band). At lower values of the SFD extinction, we find that the sky surface density of galaxies increases with increasing extinction, precisely the opposite of the effect expected from Galactic dust. We suggest that the far infrared (FIR) brightness of the sky in regions of true low dust extinction is significantly ``contaminated'' by the FIR emission from background galaxies. We show that such an explanation is both qualitatively and quantitatively consistent with the available data. Based on this interpretation we conclude that systematic errors in the SFD extinction map due to extragalactic FIR emission are quite small, of order hundredths of a magnitude, but nevertheless statistically detectable. (Abridged)Publication SDSS data management and photometric quality assessment(Wiley-Blackwell, 2004) Ivezic, Z; Lupton, R. H.; Schlegel, D.; Boroski, B.; Adelman-McCarthy, J.; Yanny, B.; Kent, S.; Stoughton, C.; Finkbeiner, Douglas; Padmanabhan, N.; Rockosi, C. M.; Gunn, J. E.; Knapp, G. R.; Strauss, M. A.; Richards, G. T.; Eisenstein, D.; Nicinski, T.; Kleinman, S. J.; Krzesinski, J.; Newman, P. R.; Snedden, S.; Thakar, A. R.; Szalay, A.; Munn, J. A.; Smith, J. A.; Tucker, D.; Lee, B. C.We summarize the Sloan Digital Sky Survey data acquisition and processing steps, and describe runQA, a pipeline designed for automated data quality assessment. In particular, we show how the position of the stellar locus in color-color diagrams can be used to estimate the accuracy of photometric zeropoint calibration to better than 0.01 mag in 0.03 deg2 patches. Using this method, we estimate that typical photometric zeropoint calibration errors for SDSS imaging data are not larger than ~0.01 mag in the g, r, and i bands, 0.02 mag in the z band, and 0.03 mag in the u band (root-mean-scatter for zeropoint offsets).Publication The Sloan Digital Sky Survey monitor telescope pipeline(Wiley-Blackwell, 2006) Tucker, D.L.; Kent, S.; Richmond, M.W.; Annis, J.; Smith, J.A.; Allam, S.S.; Rodgers, C.T.; Stute, J.L.; Adelman-McCarthy, J.K.; Brinkmann, J.; Doi, M.; Finkbeiner, Douglas; Fukugita, M.; Goldston, J.; Greenway, B.; Gunn, J.E.; Hendry, J.S.; Hogg, D.W.; Ichikawa, S.-I.; Ivezić, Ž.; Knapp, G.R.; Lampeitl, H.; Lee, B.C.; Lin, H.; McKay, T.A.; Merrelli, A.; Munn, J.A.; Neilsen, E.H.; Newberg, H.J.; Richards, G.T.; Schlegel, D.J.; Stoughton, C.; Uomoto, A.; Yanny, B.The photometric calibration of the Sloan Digital Sky Survey (SDSS) is a multi-step process which involves data from three different telescopes: the 1.0-m telescope at the US Naval Observatory (USNO), Flagstaff Station, Arizona (which was used to establish the SDSS standard star network); the SDSS 0.5-m Photometric Telescope (PT) at the Apache Point Observatory (APO), New Mexico (which calculates nightly extinctions and calibrates secondary patch transfer fields); and the SDSS 2.5-m telescope at APO (which obtains the imaging data for the SDSS proper). In this paper, we describe the Monitor Telescope Pipeline, MTPIPE, the software pipeline used in processing the data from the single-CCD telescopes used in the photometric calibration of the SDSS (i.e., the USNO 1.0-m and the PT). We also describe transformation equations that convert photometry on the USNO-1.0m u'g'r'i'z' system to photometry the SDSS 2.5m ugriz system and the results of various validation tests of the MTPIPE software. Further, we discuss the semi-automated PT factory, which runs MTPIPE in the day-to-day standard SDSS operations at Fermilab. Finally, we discuss the use of MTPIPE in current SDSS-related projects, including the Southern u'g'r'i'z' Standard Star project, the u'g'r'i'z' Open Star Clusters project, and the SDSS extension (SDSS-II).