Publications


Disentangling magnification in combined shear-clustering analyses

Monthly Notices of the Royal Astronomical Society Oxford University Press 491 (2019) 1756-1758

L Thiele, C Duncan, D Alonso


Scale invariant gravity and black hole ringdown

Physical Review D American Physical Society 101 (2020) 024011

P Ferreira, OJ Tattersall


A Search for MeV to TeV Neutrinos from Fast Radio Bursts with IceCube

The Astrophysical Journal: an international review of astronomy and astronomical physics American Astronomical Society (2020)

GW Sullivan, T Stürwald, K Tollefson, T Stuttard, L Tomankova, A Terliuk, F Tenholt, I Taboada, S Tilav, M Tselengidou, S Toscano, CF Turley, A Turcati, R Turcotte, C Tönnis, A Trettin, CF Tung, D Tosi, J Vandenbroucke, MAU Elorrieta, NV Eijndhoven, WV Driessche, S Vanheule, E Unger, M Usner

We present two searches for IceCube neutrino events coincident with 28 fast radio bursts (FRBs) and one repeating FRB. The first improves upon a previous IceCube analysis -- searching for spatial and temporal correlation of events with FRBs at energies greater than roughly 50 GeV -- by increasing the effective area by an order of magnitude. The second is a search for temporal correlation of MeV neutrino events with FRBs. No significant correlation is found in either search, therefore, we set upper limits on the time-integrated neutrino flux emitted by FRBs for a range of emission timescales less than one day. These are the first limits on FRB neutrino emission at the MeV scale, and the limits set at higher energies are an order-of-magnitude improvement over those set by any neutrino telescope.


Non-Gaussianity constraints using future radio continuum surveys and the multitracer technique

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 492 (2019) 1513-1522

Z Gomes, S Camera, C Hale, MJ Jarvis, J Fonseca

<jats:title>ABSTRACT</jats:title> <jats:p>Tighter constraints on measurements of primordial non-Gaussianity (PNG) will allow the differentiation of inflationary scenarios. The cosmic microwave background bispectrum – the standard method of measuring the local non-Gaussianity – is limited by cosmic variance. Therefore, it is sensible to investigate measurements of non-Gaussianity using the large-scale structure. This can be done by investigating the effects of non-Gaussianity on the power spectrum on large scales. In this study, we forecast the constraints on the local PNG parameter fNL that can be obtained with future radio surveys. We utilize the multitracer method that reduces the effect of cosmic variance and takes advantage of the multiple radio galaxy populations that are differently biased tracers of the same underlying dark matter distribution. Improvements on previous work include the use of observational bias and halo mass estimates, updated simulations, and realistic photometric redshift expectations, thus producing more realistic forecasts. Combinations of Square Kilometre Array simulations and radio observations were used as well as different redshift ranges and redshift bin sizes. It was found that in the most realistic case the 1σ error on fNL falls within the range 4.07–6.58, rivalling the tightest constraints currently available.</jats:p>


The optically-selected 1.4-GHz quasar luminosity function below 1 mJy

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) (2020)

E Malefahlo, MG Santos, SV White, MJ Jarvis, JTL Zwart

<jats:title>Abstract</jats:title> <jats:p>We present the radio luminosity function (RLF) of optically-selected quasars below 1 mJy, constructed by applying a Bayesian-fitting stacking technique to objects well below the nominal radio flux-density limit. We test the technique using simulated data, confirming that we can reconstruct the RLF over three orders of magnitude below the typical 5σ detection threshold. We apply our method to 1.4-GHz flux-densities from the Faint Images of the Radio Sky at Twenty-cm survey (FIRST), extracted at the positions of optical quasars from the Sloan Digital Sky Survey (SDSS) over seven redshift bins up to z = 2.15 and measure the RLF down to two orders of magnitude below the FIRST detection threshold. In the lowest redshift bin (0.2 < z < 0.45), we find that our measured RLF agrees well with deeper data from the literature. The RLF for the radio-loud quasars flattens below log10[L1.4/W Hz−1] ≈ 25.5 and becomes steeper again below log10[L1.4/W Hz−1] ≈ 24.8, where radio-quiet quasars start to emerge. The radio luminosity where radio-quiet quasars emerge coincides with the luminosity where star-forming galaxies are expected to start to dominate the radio source counts. This implies that there could be a significant contribution from star formation in the host galaxies, but additional data is required to investigate this further. The higher-redshift bins show a similar behaviour as for the lowest-z bin, implying that the same physical process may be responsible.</jats:p>


The performance of photometric reverberation mapping at high redshift and the reliability of damped random walk models

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 492 (2019) 3940-3959

DJB Smith, MJ Jarvis, SC Read, G Gürkan

<jats:title>ABSTRACT</jats:title> <jats:p>Accurate methods for reverberation mapping using photometry are highly sought after since they are inherently less resource intensive than spectroscopic techniques. However, the effectiveness of photometric reverberation mapping for estimating black hole masses is sparsely investigated at redshifts higher than z ≈ 0.04. Furthermore, photometric methods frequently assume a damped random walk (DRW) model, which may not be universally applicable. We perform photometric reverberation mapping using the javelin photometric DRW model for the QSO SDSS-J144645.44+625304.0 at z = 0.351 and estimate the Hβ lag of $65^{+6}_{-1}$ d and black hole mass of $10^{8.22^{+0.13}_{-0.15}}\, \mathrm{M_{\odot }}$. An analysis of the reliability of photometric reverberation mapping, conducted using many thousands of simulated CARMA process light curves, shows that we can recover the input lag to within 6 per cent on average given our target’s observed signal-to-noise of >20 and average cadence of 14 d (even when DRW is not applicable). Furthermore, we use our suite of simulated light curves to deconvolve aliases and artefacts from our QSO’s posterior probability distribution, increasing the signal-to-noise on the lag by a factor of ∼2.2. We exceed the signal-to-noise of the Sloan Digital Sky Survey Reverberation Mapping Project (SDSS-RM) campaign with a quarter of the observing time per object, resulting in a ∼200 per cent increase in signal-to-noise efficiency over SDSS-RM.</jats:p>


Time-integrated Neutrino Source Searches with 10 years of IceCube Data

Physical Review Letters American Physical Society (2020)

S Robertson, M Rongen, C Rott, T Ruhe, D Ryckbosch, D Rysewyk, I Safa, SES Herrera, A Sandrock, J Sandroos, M Santander, SUBIR Sarkar, S SARKAR, K Satalecka, M Schaufel, H Schieler, P Schlunder, T Schmidt, A Schneider, J Schneider, FG Schröder, L Schumacher, S Sclafani, D Seckel, S Seunarine

This paper presents the results from point-like neutrino source searches using ten years of IceCube data collected between Apr.~6, 2008 and Jul.~10, 2018. We evaluate the significance of an astrophysical signal from a point-like source looking for an excess of clustered neutrino events with energies typically above $\sim1\,$TeV among the background of atmospheric muons and neutrinos. We perform a full-sky scan, a search within a selected source catalog, a catalog population study, and three stacked Galactic catalog searches. The most significant point in the Northern hemisphere from scanning the sky is coincident with the Seyfert II galaxy NGC 1068, which was included in the source catalog search. The excess at the coordinates of NGC 1068 is inconsistent with background expectations at the level of $2.9\,\sigma$ after accounting for statistical trials. The combination of this result along with excesses observed at the coordinates of three other sources, including TXS 0506+056, suggests that, collectively, correlations with sources in the Northern catalog are inconsistent with background at 3.3$\,\sigma$ significance. These results, all based on searches for a cumulative neutrino signal integrated over the ten years of available data, motivate further study of these and similar sources, including time-dependent analyses, multimessenger correlations, and the possibility of stronger evidence with coming upgrades to the detector.


Development of an analysis to probe the neutrino mass ordering with atmospheric neutrinos using three years of IceCube DeepCore data: IceCube Collaboration

European Physical Journal C 80 (2020)

MG Aartsen, M Ackermann, J Adams, JA Aguilar, M Ahlers, M Ahrens, C Alispach, K Andeen, T Anderson, I Ansseau, G Anton, C Argüelles, J Auffenberg, S Axani, P Backes, H Bagherpour, X Bai, A Barbano, SW Barwick, V Baum, R Bay, JJ Beatty, KH Becker, JB Tjus, S BenZvi, D Berley, E Bernardini, DZ Besson, G Binder, D Bindig, E Blaufuss, S Blot, C Bohm, M Börner, S Böser, O Botner, E Bourbeau, J Bourbeau, F Bradascio, J Braun, HP Bretz, S Bron, J Brostean-Kaiser, A Burgman, RS Busse, T Carver, C Chen, E Cheung, D Chirkin, K Clark, L Classen, GH Collin, JM Conrad, P Coppin, P Correa, DF Cowen, R Cross, P Dave, JPAM de André, C De Clercq, JJ DeLaunay, H Dembinski, K Deoskar, S De Ridder, P Desiati, KD de Vries, G de Wasseige, M de With, T DeYoung, A Diaz, JC Díaz-Vélez, H Dujmovic, M Dunkman, E Dvorak, B Eberhardt, T Ehrhardt, B Eichmann, P Eller, JJ Evans, PA Evenson, S Fahey, AR Fazely, J Felde, K Filimonov, C Finley, A Franckowiak, E Friedman, A Fritz, TK Gaisser, J Gallagher, E Ganster, S Garrappa, L Gerhardt, K Ghorbani, T Glauch, T Glüsenkamp, A Goldschmidt, JG Gonzalez, D Grant, Z Griffith

© 2020, The Author(s). The Neutrino Mass Ordering (NMO) remains one of the outstanding questions in the field of neutrino physics. One strategy to measure the NMO is to observe matter effects in the oscillation pattern of atmospheric neutrinos above ∼1GeV, as proposed for several next-generation neutrino experiments. Moreover, the existing IceCube DeepCore detector can already explore this type of measurement. We present the development and application of two independent analyses to search for the signature of the NMO with three years of DeepCore data. These analyses include a full treatment of systematic uncertainties and a statistically-rigorous method to determine the significance for the NMO from a fit to the data. Both analyses show that the dataset is fully compatible with both mass orderings. For the more sensitive analysis, we observe a preference for normal ordering with a p-value of pIO= 15.3 % and CL s= 53.3 % for the inverted ordering hypothesis, while the experimental results from both analyses are consistent within their uncertainties. Since the result is independent of the value of δCP and obtained from energies Eν≳5GeV, it is complementary to recent results from long-baseline experiments. These analyses set the groundwork for the future of this measurement with more capable detectors, such as the IceCube Upgrade and the proposed PINGU detector.


Tomographic measurement of the intergalactic gas pressure through galaxy–tSZ cross-correlations

Monthly Notices of the Royal Astronomical Society Oxford University Press 491 (2019) 5464-5480

N Koukoufilippas, D Alonso, M Bilicki, JA Peacock

We cross-correlate maps of the thermal Sunyaev–Zeldovich (tSZ) Compton-y parameter published by Planck with the projected distribution of galaxies in a set of low-redshift tomographic bins. We use the nearly full-sky 2MASS Photometric Redshift and WISE × SuperCOSMOS public catalogues, covering the redshift range z ≲ 0.4. Our measurements allow us to place constraints on the redshift dependence of the mass–observable relation for tSZ cluster count analyses in terms of the so-called hydrostatic mass bias parameter 1−bH⁠. These results can also be interpreted as measurements of the bias-weighted average gas pressure 〈bPe〉 as a function of redshift, a quantity that can be related to the thermodynamics of gas inside haloes and used to constrain energy injection processes. We measure 1−bH with ∼13 per cent precision in six equispaced redshift bins, and find no evidence for a redshift-dependent mass bias parameter, in agreement with previous analyses. Our mean value of 1−bH=0.59±0.03 is also in good agreement with the one estimated by the joint analysis of Planck cluster counts and cosmic microwave background anisotropies. Our measurements of 〈bPe〉, at the level of ∼10 per cent in each bin, are the most stringent constraints on the redshift dependence of this parameter to date, and agree well both with previous measurements and with theoretical expectations from shock-heating models.


Design and Performance of the first IceAct Demonstrator at the South Pole

Journal of Instrumentation IOP Publishing (2020)

GW Sullivan, I Taboada, A Taketa, S Ter-Antonyan, HKM Tanaka, F Tenholt, A Terliuk, S Tilav, K Tollefson, L Tomankova, C Tönnis, S Toscano, D Tosi, M Tselengidou, A Turcati, A Trettin, CF Tung, R Turcotte, CF Turley, MAU Elorrieta, B Ty, E Unger, J Vandenbroucke, M Usner, WV Driessche

In this paper we describe the first results of a compact imaging air-Cherenkov telescope, IceAct, operating in coincidence with the IceCube Neutrino Observatory (IceCube) at the geographic South Pole. An array of IceAct telescopes (referred to as the IceAct project) is under consideration as part of the IceCube-Gen2 extension to IceCube. Surface detectors in general will be a powerful tool in IceCube-Gen2 for distinguishing astrophysical neutrinos from the dominant backgrounds of cosmic-ray induced atmospheric muons and neutrinos: the IceTop array is already in place as part of IceCube, but has a high energy threshold. Although the duty cycle will be lower for the IceAct telescopes than the present IceTop tanks, the IceAct telescopes may prove to be more effective at lowering the detection threshold for air showers. Additionally, small imaging air-Cherenkov telescopes in combination with IceTop, the deep IceCube detector or other future detector systems might improve measurements of the composition of the cosmic ray energy spectrum. In this paper we present measurements of a first 7-pixel imaging air Cherenkov telescope demonstrator, proving the capability of this technology to measure air showers at the South Pole in coincidence with IceTop and the deep IceCube detector.


Measuring the H I mass function below the detection threshold

Monthly Notices of the Royal Astronomical Society Oxford University Press 491 (2019) 1227–1242-

H Pan, X Kang, I Heywood, M Jarvis, N Maddox, BS Frank

We present a Bayesian stacking technique to directly measure the H i mass function (HIMF) and its evolution with redshift using galaxies formally below the nominal detection threshold. We generate galaxy samples over several sky areas given an assumed HIMF described by a Schechter function and simulate the H i emission lines with different levels of background noise to test the technique. We use Multinest to constrain the parameters of the HIMF in a broad redshift bin, demonstrating that the HIMF can be accurately reconstructed, using the simulated spectral cube far below the H i mass limit determined by the 5σ flux-density limit, i.e. down to MHI = 107.5 M⊙ over the redshift range 0 < z < 0.55 for this particular simulation, with a noise level similar to that expected for the MIGHTEE survey. We also find that the constraints on the parameters of the Schechter function, φ⋆, M⋆ and α can be reliably fit, becoming tighter as the background noise decreases as expected, although the constraints on the redshift evolution are not significantly affected. All the parameters become better constrained as the survey area increases. In summary, we provide an optimal method for estimating the H i mass at cosmological distances that allows us to constrain the H i mass function below the detection threshold in forthcoming H i surveys. This study is a first step towards the measurement of the HIMF at high (z > 0.1) redshifts.


Is there really a `Hubble tension'?

arXiv (2019)

M Rameez, SUBIR Sarkar

Errors in redshift measurements as small as $\Delta z \sim 0.0001$ can have significant impact on the value of inferred cosmological parameters such as $H_0$ (Davis et al. 2019). We have earlier reported that the redshifts of over 100 Type Ia supernovae (SNe Ia) which are in common between the SDSSII-SNLS3 Joint Lightcurve Analysis (JLA) catalogue (Betoule et al. 2014) and the subsequent Pantheon compilation (Scolnic et al. 2018) are discrepant - some by as much as $\Delta z \sim 0.1$ (Rameez 2019a). We study the impact of this on the inferred value of $H_0$ using calibrations of the supernova absolute magnitude via the 'local distance ladder' (Riess et al. 2016). For supernovae with $\Delta z > 0.025$, the JLA redshifts favour $H_0 \sim 72$~km~s$^{-1}$Mpc$^{-1}$, while the Pantheon redshifts favour $H_0 \sim 68$~km~s$^{-1}$Mpc$^{-1}$. For comparison the value inferred (assuming the flat $\Lambda$CDM model) from the Planck data on CMB anisotropies is $H_0 \sim 67.4 \pm 0.5$~km~s$^{-1}$Mpc$^{-1}$ (Aghanim et al. 2018). Thus the systematic uncertainties that apparently still plague the distance ladder measurement of $H_0$ undermine the significance of the discrepancy claimed by Riess et al. (2019).


Evidence for anisotropy of cosmic acceleration

Astronomy and Astrophysics: a European journal EDP Sciences (2019)

J Colin, R Mohayaee, M Rameez, S Sarkar

Observations reveal a `bulk flow' in the local Universe which is faster and extends to much larger scales than is expected around a typical observer in the standard $\Lambda$CDM cosmology. This is expected to result in a scale-dependent dipolar modulation of the acceleration of the expansion rate inferred from observations of objects within the bulk flow. From a maximum-likelihood analysis of the Joint Lightcurve Analysis (JLA) catalogue of Type Ia supernovae we find that the deceleration parameter, in addition to a small monopole, indeed has a much bigger dipole component aligned with the CMB dipole which falls exponentially with redshift $z$: $q_0 = q_\mathrm{m} + \vec{q}_\mathrm{d}.\hat{n}\exp(-z/S)$. The best fit to data yields $q_\mathrm{d} = -8.03$ and $S = 0.0262~(\Rightarrow d \sim 100~\mathrm{Mpc})$, rejecting isotropy ($q_\mathrm{d} = 0$) with $3.9\sigma$ statistical significance, while $q_\mathrm{m} = -0.157$ and consistent with no acceleration ($q_\mathrm{m} = 0$) at $1.4\sigma$. Thus the cosmic acceleration deduced from supernovae may be an artefact of our being non-Copernican observers, rather than evidence for a dominant component of `dark energy' in the Universe.


Simulating MOS science on the ELT: Ly alpha forest tomography

ASTRONOMY & ASTROPHYSICS 632 (2019) ARTN A94

JEG Devriendt, P Petitjean, Y Dubois, E Gendron, F Hammer, S Morris, L Kaper, R Sanchez-Janssen, SD Vergani, N Pirzkal, A Slyz, Y Yang, J Japelj, C Laigle, H Rahmani, C Pichon, M Puech

Mapping of the large-scale structure through cosmic time has numerous applications in the studies of cosmology and galaxy evolution. At $z > 2$, the structure can be traced by the neutral intergalactic medium (IGM) by way of observing the Ly$\alpha$, forest towards densely-sampled lines-of-sight of bright background sources, such as quasars and star forming galaxies. We investigate the scientific potential of MOSAIC, a planned multi-object spectrograph on the European Extremely Large Telescope (ELT), for the 3D mapping of the IGM at $z \gtrsim 3$. We simulate a survey of $3 \lesssim z \lesssim 4$ galaxies down to a limiting magnitude of $m_{r}\sim 25.5$ mag in an area of 1 degree$^2$ in the sky. Galaxies and their spectra (including the line-of-sight Ly$\alpha$ absorption) are taken from the lightcone extracted from the Horizon-AGN cosmological hydrodynamical simulation. The quality of the reconstruction of the original density field is studied for different spectral resolutions and signal-to-noise ratios of the spectra. We demonstrate that the minimum $S/N$ (per resolution element) of the faintest galaxies that such survey has to reach is $S/N = 4$. We show that a survey with such sensitivity enables a robust extraction of cosmic filaments and the detection of the theoretically-predicted galaxy stellar mass and star-formation rate gradients towards filaments. By simulating the realistic performance of MOSAIC we obtain $S/N(T_{\rm obs}, R, m_{r})$ scaling relations. We estimate that $\lesssim 35~(65)$ nights of observation time are required to carry out the survey with the instrument's high multiplex mode and with the spectral resolution of $R=1000~(2000)$. A survey with a MOSAIC-concept instrument on the ELT is found to enable the mapping of the IGM at $z > 3$ on Mpc scales, and as such will be complementary to and competitive with other planned IGM tomography surveys. [abridged]


Cosmic ray spectrum and composition from PeV to EeV using 3 years of data from IceTop and IceCube

PHYSICAL REVIEW D 100 (2019) ARTN 082002

MG Aartsen, M Ackermann, J Adams, JA Aguilar, M Ahlers, M Ahrens, C Alispach, K Andeen, T Anderson, I Ansseau, G Anton, C Arguelles, J Auffenberg, S Axani, P Backes, H Bagherpour, X Bai, A Barbano, SW Barwick, V Baum, S Baur, R Bay, JJ Beatty, K-H Becker, JB Tjus, S BenZvi, D Berley, E Bernardini, DZ Besson, G Binder, D Bindig, E Blaufuss, S Blot, C Bohm, M Boerner, S Boeser, O Botner, J Boettcher, E Bourbeau, J Bourbeau, F Bradascio, J Braun, H-P Bretz, S Bron, J Brostean-Kaiser, A Burgman, J Buscher, RS Busse, T Carver, C Chen, E Cheung, D Chirkin, K Clark, L Classen, GH Collin, JM Conrad, P Coppin, P Correa, DF Cowen, R Cross, P Dave, JPAM de Andre, C De Clercq, JJ DeLaunay, H Dembinski, K Deoskar, S De Ridder, P Desiati, KD de Vries, G de Wasseige, M de With, T DeYoung, A Diaz, JC Diaz-Velez, H Dujmovic, M Dunkman, E Dvorak, B Eberhardt, T Ehrhardt, P Eller, PA Evenson, S Fahey, AR Fazely, J Felde, T Feusels, K Filimonov, C Finley, A Franckowiak, E Friedman, A Fritz, TK Gaisser, J Gallagher, E Ganster, S Garrappa, L Gerhardt, K Ghorbani, T Glauch, T Gluesenkamp, A Goldschmidt, JG Gonzalez, D Grant, Z Griffith, M Guender, M Guenduez, C Haack, A Hallgren, L Halve, F Halzen, K Hanson, D Hebecker, D Heereman, P Heix, K Helbing, R Hellauer, F Henningsen, S Hickford, J Hignight, GC Hill, KD Hoffman, R Hoffmann, T Hoinka, B Hokanson-Fasig, K Hoshina, F Huang, M Huber, K Hultqvist, M Huennefeld, R Hussain, S In, N Iovine, A Ishihara, E Jacobi, GS Japaridze, M Jeong, K Jero, BJP Jones, F Jonske, R Joppe, W Kang, A Kappes, D Kappesser, T Karg, M Karl, A Karle, U Katz, M Kauer, JL Kelley, A Kheirandish, J Kim, T Kintscher, J Kiryluk, T Kittler, SR Klein, R Koirala, H Kolanoski, L Koepke, C Kopper, S Kopper, DJ Koskinen, M Kowalski, K Krings, G Krueckl, N Kulacz, S Kunwar, N Kurahashi, A Kyriacou, M Labare, JL Lanfranchi, MJ Larson, F Lauber, JP Lazar, K Leonard, M Leuermann, QR Liu, E Lohfink, CJL Mariscal, L Lu, F Lucarelli, J Lunemann, W Luszczak, J Madsen, G Maggi, KBM Mahn, Y Makino, P Mallik, K Mallot, S Mancina, IC Mari, R Maruyama, K Mase, R Maunu, K Meagher, M Medici, A Medina, M Meier, S Meighen-Berger, T Menne, G Merino, T Meures, S Miarecki, J Micallef, G Momente, T Montaruli, RW Moore, R Morse, M Moulai, P Muth, R Nagai, R Nahnhauer, P Nakarmi, U Naumann, G Neer, H Niederhausen, SC Nowicki, DR Nygren, AO Pollmann, A Olivas, A O'Murchadha, E O'Sullivan, T Palczewski, H Pandya, DV Pankova, N Park, P Peiffer, CP de los Heros, S Philippen, D Pieloth, E Pinat, A Pizzuto, M Plum, A Porcelli, PB Price, GT Przybylski, C Raab, A Raissi, M Rameez, L Rauch, K Rawlins, IC Rea, R Reimann, B Relethford, G Renzi, E Resconi, W Rhode, M Richman, S Robertson, M Rongen, C Rott, T Ruhe, D Ryckbosch, D Rysewyk, I Safa, SES Herrera, A Sandrock, J Sandroos, M Santander, S Sarkar, K Satalecka, M Schaufel, P Schlunder, T Schmidt, A Schneider, J Schneider, L Schumacher, S Sclafani, D Seckel, S Seunarine, S Shefali, M Silva, R Snihur, J Soedingrekso, D Soldin, M Song, GM Spiczak, C Spiering, J Stachurska, M Stamatikos, T Stanev, A Stasik, R Stein, J Stettner, A Steuer, T Stezelberger, RG Stokstad, A Stossl, NL Strotjohann, T Stuerwald, T Stuttard, GW Sullivan, M Sutherland, I Taboada, F Tenholt, S Ter-Antonyan, A Terliuk, S Tilav, L Tomankova, C Tonnis, S Toscano, D Tosi, M Tselengidou, CF Tung, A Turcati, R Turcotte, CF Turley, B Ty, E Unger, MAU Elorrieta, M Usner, J Vandenbroucke, W Van Driessche, D van Eijk, N van Eijndhoven, S Vanheule, J van Santen, M Vraeghe, C Walck, A Wallace, M Wallraff, N Wandkowsky, TB Watson, C Weaver, MJ Weiss, J Weldert, C Wendt, J Werthebach, S Westerhoff, BJ Whelan, N Whitehorn, K Wiebe, CH Wiebusch, L Wille, DR Williams, L Wills, M Wolf, J Wood, TR Wood, K Woschnagg, G Wrede, DL Xu, XW Xu, Y Xu, JP Yanez, G Yodh, S Yoshida, T Yuan, M Zoecklein, I Collaboration


Efficient propagation of systematic uncertainties from calibration to analysis with the SnowStorm method in IceCube

Journal of Cosmology and Astroparticle Physics IOP Publishing 2019 (2019) 048-048

MG Aartsen, M Ackermann, J Adams, JA Aguilar, M Ahlers, C Alispach, BA Atoum, K Andeen, T Anderson, I Ansseau, G Anton, C Argüelles, J Auffenberg, S Axani, P Backes, H Bagherpour, X Bai, AB V., A Barbano, SW Barwick, B Bastian, V Baum, S Baur, R Bay, JJ Beatty, K-H Becker, JB Tjus, S BenZvi, D Berley, E Bernardini, DZ Besson, G Binder, D Bindig, E Blaufuss, S Blot, C Bohm, M Börner, S Böser, O Botner, J Böttcher, E Bourbeau, J Bourbeau, F Bradascio, J Braun, S Bron, J Brostean-Kaiser, A Burgman, J Buscher, RS Busse, T Carver, C Chen, E Cheung, D Chirkin, S Choi, K Clark, L Classen, A Coleman, GH Collin, JM Conrad, P Coppin, P Correa, DF Cowen, R Cross, P Dave, CD Clercq, JJ DeLaunay, H Dembinski, K Deoskar, SD Ridder, P Desiati, KD de Vries, G de Wasseige, M de With, T DeYoung, A Diaz, JC Díaz-Vélez, H Dujmovic, M Dunkman, E Dvorak, B Eberhardt, T Ehrhardt, P Eller, R Engel, PA Evenson, S Fahey, AR Fazely, J Felde, K Filimonov, C Finley, A Franckowiak, E Friedman, A Fritz, TK Gaisser, J Gallagher, E Ganster, S Garrappa, L Gerhardt, K Ghorbani, T Glauch, T Glüsenkamp, A Goldschmidt, JG Gonzalez, D Grant, Z Griffith, S Griswold, M Günder, M Gündüz, C Haack, A Hallgren, L Halve, F Halzen, K Hanson, A Haungs, D Hebecker, D Heereman, P Heix, K Helbing, R Hellauer, F Henningsen, S Hickford, J Hignight, GC Hill, KD Hoffman, R Hoffmann, T Hoinka, B Hokanson-Fasig, K Hoshina, F Huang, M Huber, T Huber, K Hultqvist, M Hünnefeld, R Hussain, S In, N Iovine, A Ishihara, GS Japaridze, M Jeong, K Jero, BJP Jones, F Jonske, R Joppe, D Kang, W Kang, A Kappes, D Kappesser, T Karg, M Karl, A Karle, U Katz, M Kauer, JL Kelley, A Kheirandish, J Kim, T Kintscher, J Kiryluk, T Kittler, SR Klein, R Koirala, H Kolanoski, L Köpke, C Kopper, S Kopper, DJ Koskinen, M Kowalski, K Krings, G Krückl, N Kulacz, N Kurahashi, A Kyriacou, M Labare, JL Lanfranchi, MJ Larson, F Lauber, JP Lazar, K Leonard, A Leszczyńska, M Leuermann, QR Liu, E Lohfink, CJL Mariscal, L Lu, F Lucarelli, J Lünemann, W Luszczak, Y Lyu, WY Ma, J Madsen, G Maggi, KBM Mahn, Y Makino, P Mallik, K Mallot, S Mancina, IC Mariş, R Maruyama, K Mase, R Maunu, F McNally, K Meagher, M Medici, A Medina, M Meier, S Meighen-Berger, T Menne, G Merino, T Meures, J Micallef, D Mockler, G Momenté, T Montaruli, RW Moore, R Morse, M Moulai, P Muth, R Nagai, U Naumann, G Neer, H Niederhausen, SC Nowicki, DR Nygren, AO Pollmann, M Oehler, A Olivas, A O'Murchadha, E O'Sullivan, T Palczewski, H Pandya, DV Pankova, N Park, P Peiffer, C Pérez de los Heros, S Philippen, D Pieloth, E Pinat, A Pizzuto, M Plum, A Porcelli, PB Price, GT Przybylski, C Raab, A Raissi, M Rameez, L Rauch, K Rawlins, IC Rea, R Reimann, B Relethford, M Renschler, G Renzi, E Resconi, W Rhode, M Richman, S Robertson, M Rongen, C Rott, T Ruhe, D Ryckbosch, D Rysewyk, I Safa, SES Herrera, A Sandrock, J Sandroos, M Santander, S Sarkar, S Sarkar, K Satalecka, M Schaufel, H Schieler, P Schlunder, T Schmidt, A Schneider, J Schneider, FG Schröder, L Schumacher, S Sclafani, D Seckel, S Seunarine, S Shefali, M Silva, R Snihur, J Soedingrekso, D Soldin, M Song, GM Spiczak, C Spiering, J Stachurska, M Stamatikos, T Stanev, R Stein, P Steinmüller, J Stettner, A Steuer, T Stezelberger, RG Stokstad, A Stößl, NL Strotjohann, T Stürwald, T Stuttard, GW Sullivan, I Taboada, F Tenholt, S Ter-Antonyan, A Terliuk, S Tilav, K Tollefson, L Tomankova, C Tönnis, S Toscano, D Tosi, A Trettin, M Tselengidou, CF Tung, A Turcati, R Turcotte, CF Turley, B Ty, E Unger, MAU Elorrieta, M Usner, J Vandenbroucke, WV Driessche, DV Eijk, NV Eijndhoven, S Vanheule, JV Santen, M Vraeghe, C Walck, A Wallace, M Wallraff, N Wandkowsky, TB Watson, C Weaver, A Weindl, MJ Weiss, J Weldert, C Wendt, J Werthebach, BJ Whelan, N Whitehorn, K Wiebe, CH Wiebusch, L Wille, DR Williams, L Wills, M Wolf, J Wood, TR Wood, K Woschnagg, G Wrede, DL Xu, XW Xu, Y Xu, JP Yanez, G Yodh, S Yoshida, T Yuan, M Zöcklein


Testing self-interacting dark matter with galaxy warps

PHYSICAL REVIEW D 100 (2019) ARTN 123006

K Pardo, H Desmond, PG Ferreira


A response to Rubin & Heitlauf: "Is the expansion of the universe accelerating? All signs \emph{still} point to yes"

arXiv (2019)

J Colin, SUBIR Sarkar, R Mohayaee, M Rameez

We have shown (Colin et al. 2019) that the acceleration of the Hubble expansion rate inferred from Type Ia supernovae is essentially a dipole with 3.9$\sigma$ significance, approximately aligned with the CMB dipole, while its monopole component which may be interpreted as due to a Cosmological Constant (or more generally dark energy) is consistent with zero at 1.4$\sigma$. This is challenged by Rubin & Heitlauf (2019) who assert that we incorrectly assumed the supernova light-curve parameters to be independent of redshift, and erred further in considering their measured redshifts (in the heliocentric frame) rather than transforming them to the CMB frame (in which the universe supposedly looks isotropic). We emphasize that our procedure is justified and that their criticism serves only to highlight the rather "arbitrary corrections" that are made to the data in order to infer isotropic cosmic acceleration. This is a vivid illustration of the 'Cosmological Fitting Problem' faced by observers who live in an inhomogeneous universe but still use the maximally symmetric FLRW cosmolgy to interpret observations.


Constraints on Neutrino Emission from Nearby Galaxies Using the 2MASS Redshift Survey and IceCube

arXiv (2019)

A O'Murchadha, E O'Sullivan, T Palczewski, AO Pollmann, SC Nowicki, H Pandya, A Olivas, M Oehler, Nygren, S Philippen, DV Pankova, CPDL Heros, D Pieloth, A Pizzuto, E Bourbeau, P Peiffer, E Pinat, N Park, JG Gonzalez, A Hallgren, M Gündüz, S Griswold, Z Griffith, R Halliday, M Günder

The distribution of galaxies within the local universe is characterized by anisotropic features. Observatories searching for the production sites of astrophysical neutrinos can take advantage of these features to establish directional correlations between a neutrino dataset and overdensities in the galaxy distribution in the sky. The results of two correlation searches between a seven-year time-integrated neutrino dataset from the IceCube Neutrino Observatory, and the 2MASS Redshift Survey (2MRS) catalog are presented here. The first analysis searches for neutrinos produced via interactions between diffuse intergalactic Ultra-High Energy Cosmic Rays (UHECRs) and the matter contained within galaxies. The second analysis searches for low-luminosity sources within the local universe, which would produce subthreshold multiplets in the IceCube dataset that directionally correlate with galaxy distribution. No significant correlations were observed in either analyses. Constraints are presented on the flux of neutrinos originating within the local universe through diffuse intergalactic UHECR interactions, as well as on the density of standard candle sources of neutrinos at low luminosities.


Extracting the global signal from 21-cm fluctuations: The multi-tracer approach

Monthly Notices of the Royal Astronomical Society Oxford University Press (2019)

A Fialkov, R Barkana, M Jarvis

The multi-tracer technique employs a ratio of densities of two differently biased galaxy samples that trace the same underlying matter density field, and was proposed to alleviate the cosmic variance problem. Here we propose a novel application of this approach, applying it to two different tracers one of which is the 21-cm signal of neutral hydrogen from the epochs of reionization and comic dawn. The second tracer is assumed to be a sample of high-redshift galaxies, but the approach can be generalized and applied to other high-redshift tracers. We show that the anisotropy of the ratio of the two density fields can be used to measure the sky-averaged 21-cm signal, probe the spectral energy distribution of radiative sources that drive this signal, and extract large-scale properties of the second tracer, e.g., the galaxy bias. Using simulated 21-cm maps and mock galaxy samples, we find that the method works well for an idealized galaxy survey. However, in the case of a more realistic galaxy survey which only probes highly biased luminous galaxies, the inevitable Poisson noise makes the reconstruction far more challenging. This difficulty can be mitigated with the greater sensitivity of future telescopes along with larger survey volumes.

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