REINABELLE REYES

University of the Philippines

Sex: Female

Education: 

Princeton University, Doctor of Philosophy Astrophysics, 2006-2011

Abdus Salam International Center for Theoretical Physics, Diploma in High Energy Physics, 2005-2006

Ateneo de Manila University, Bachelor of Science in Physics, 2001-2005

Field of Specialization

Data Science

Data Analytics

Physics

Researches:

 

Article Title: Predicting Galaxy Star Formation Rates via the Co-evolution of Galaxies and Halos

Authors: Douglas F. Watson, Andrew P. Hearin, Andreas A. Berlind, Matthew A. Becker, Peter S. Behroozi, Ramin A. Skibba, Reinabelle Reyes, Andrew R. Zentner, 

Publication title: Monthly Notices of the Royal Astronomical Society 446(1), March 2014




Abstract: 

In this paper, we test the age matching hypothesis that the star formation rate (SFR) of a galaxy of fixed stellar mass is determined by its dark matter halo formation history, e.g. more quiescent galaxies reside in older haloes. We present new Sloan Digital Sky Survey measurements of the galaxy two-point correlation function and galaxy–galaxy lensing as a function of stellar mass and SFR, separated into quenched and star-forming galaxy samples to test this simple model. We find that our age matching model is in excellent agreement with these new measurements. We also find that our model is able to predict: (1) the relative SFRs of central and satellite galaxies, (2) the SFR dependence of the radial distribution of satellite galaxy populations within galaxy groups, rich groups, and clusters and their surrounding larger scale environments, and (3) the interesting feature that the satellite quenched fraction as a function of projected radial distance from the central galaxy exhibits an ∼r−.15 slope, independent of environment. These accurate predictions are intriguing given that we do not explicitly model satellite-specific processes after infall, and that in our model the virial radius does not mark a special transition region in the evolution of a satellite. The success of the model suggests that present-day galaxy SFR is strongly correlated with halo mass assembly history.

Full text link: https://tinyurl.com/yamz34wv

 

Article title: The Dark Side of Galaxy Color: evidence from new SDSS measurements of galaxy clustering and lensing

Authors: Andrew P. Hearin, Douglas F. Watson, Matthew R. Becker, Reinabelle Reyes, Andreas A. Berlind, Andrew R. Zentner

Publication title: Monthly Notices of the Royal Astronomical Society 444(1), October 2013

 

Abstract

The age-matching model has recently been shown to predict correctly the luminosity L and g − r colour of galaxies residing within dark matter haloes. The central tenet of the model is intuitive: older haloes tend to host galaxies with older stellar populations. In this paper, we demonstrate that age matching also correctly predicts the g − r colour trends exhibited in a wide variety of statistics of the galaxy distribution for stellar mass M* threshold samples. In particular, we present new Sloan Digital Sky Survey (SDSS) measurements of galaxy clustering and the galaxy–galaxy lensing signal ΔΣ as a function of M* and g − r colour, and show that age matching exhibits remarkable agreement with these and other statistics of low-redshift galaxies. In so doing, we also demonstrate good agreement between the galaxy–galaxy lensing observed by SDSS and the ΔΣ signal predicted by abundance matching, a new success of this model. We describe how age matching is a specific example of a larger class of conditional abundance matching models (CAM), a theoretical framework we introduce here for the first time. CAM provides a general formalism to study correlations at fixed mass between any galaxy property and any halo property. The striking success of our simple implementation of CAM suggests that this technique has the potential to describe the same set of data as alternative models, but with a dramatic reduction in the required number of parameters. CAM achieves this reduction by exploiting the capability of contemporary N-body simulations to determine dark matter halo properties other than mass alone, which distinguishes our model from conventional approaches to the galaxy–halo connection.

Full text link: https://tinyurl.com/yb85jwdx

 

Article title: Is LambdaCDM consistent with the Tully-Fisher relation?

Author: Reinabelle Reyes, Gunn, J.E., Mandelbaum, R.

Publication title : Probes of Dark Matter on Galaxy Scales, AAS Topical Conference Series Vol. 1. (Proceedings of the conference held 14-19 July 2013 in Monterey, CA. Bulletin of the American Astronomical Society, Vol. 45, #7, #403.04)

 

Abstract: 

We consider the question of the origin of the Tully-Fisher relation in LambdaCDM cosmology. Reproducing the observed tight relation between stellar masses and rotation velocities of disk galaxies presents a challenge for semi-analytical models and hydrodynamic simulations of galaxy formation. Here, our goal is to construct a suite of galaxy mass models that is fully consistent with observations, and that also reproduces the observed Tully-Fisher relation. We take advantage of a well-defined sample of disk galaxies in SDSS with measured rotation velocities (from long-slit spectroscopy of H-alpha), stellar bulge and disk profiles (from fits to SDSS images), and average dark matter halo masses (from stacked weak lensing of a larger, similarly-selected sample). The primary remaining freedom in the mass models come from the final dark matter halo profile (after contraction from baryon infall and, possibly, feedback) and the stellar IMF. We find that the observed velocities are reproduced by models with Kroupa IMF and NFW (i.e., unmodified) dark matter haloes for galaxies with stellar masses 10^9-10^10 M_sun. For higher stellar masses, models with contracted NFW haloes are favored. A scenario in which the amount of halo contraction varies with stellar mass is able to reproduce the observed Tully-Fisher relation over the full stellar mass range of our sample from 10^9 to 10^11 M_sun. We present this as a proof-of-concept for consistency between LambdaCDM and the Tully-Fisher relation.

 

Article title: Cosmological parameter constraints from galaxy-galaxy lensing and galaxy clustering with the SDSS DR7

Authors: Rachel Mandelbaum, Anze Slosar, Tobias Baldauf, Uros Seljak, Christopher Hirata, Reinabelle Reyes, Robert E. Smith

Publication title:  Monthly Notices of the Royal Astronomical Society 432(2,) July 2012

 

Abstract

Recent studies have shown that the cross-correlation coefficient between galaxies and dark matter is very close to unity on scales outside a few virial radii of galaxy haloes, independent of the details of how galaxies populate dark matter haloes. This finding makes it possible to determine the dark matter clustering from measurements of galaxy–galaxy weak lensing and galaxy clustering. We present new cosmological parameter constraints based on large-scale measurements of spectroscopic galaxy samples from the Sloan Digital Sky Survey (SDSS) data release 7. We generalize the approach of Baldauf et al. to remove small-scale information (below 2 and 4 h−1 Mpc for lensing and clustering measurements, respectively), where the cross-correlation coefficient differs from unity. We derive constraints for three galaxy samples covering 7131 deg2, containing 69 150, 62 150 and 35 088 galaxies with mean redshifts of 0.11, 0.28 and 0.40. We clearly detect scale-dependent galaxy bias for the more luminous galaxy samples, at a level consistent with theoretical expectations. When we vary both σ8 and Ωm (and marginalize over non-linear galaxy bias) in a flat Λ cold dark matter model, the best-constrained quantity is σ8(Ωm/0.25)0.57 = 0.80 ± 0.05 (1σ, stat. + sys.), where statistical and systematic errors (photometric redshift and shear calibration) have comparable contributions, and we have fixed ns = 0.96 and h = 0.7. These strong constraints on the matter clustering suggest that this method is competitive with cosmic shear in current data, while having very complementary and in some ways less serious systematics. We therefore expect that this method will play a prominent role in future weak lensing surveys. When we combine these data with Wilkinson Microwave Anisotropy Probe 7-year (WMAP7) cosmic microwave background (CMB) data, constraints on σ8, Ωm, H0, wde and ∑mν become 30–80 per cent tighter than with CMB data alone, since our data break several parameter degeneracies.

 

Article title: Calibrated Tully–Fisher relations for improved estimates of disc rotation velocities

Authors: Reinabelle Reyes, R. Mandelbaum, J. E. Gunn, J. Pizagno, Claire N. Lacker

Publication title: Monthly Notices of the Royal Astronomical Society 417(3), November 2011

 

Abstract:

In this paper, we derive scaling relations between photometric observable quantities and disc galaxy rotation velocity Vrot or Tully–Fisher relations (TFRs). Our methodology is dictated by our purpose of obtaining purely photometric, minimal-scatter estimators of Vrot applicable to large galaxy samples from imaging surveys. To achieve this goal, we have constructed a sample of 189 disc galaxies at redshifts z < 0.1 with long-slit Hα spectroscopy from Pizagno et al. and new observations. By construction, this sample is a fair subsample of a large, well-defined parent disc sample of ∼170 000 galaxies selected from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7). The optimal photometric estimator of Vrot we find is stellar mass M★ from Bell et al., based on the linear combination of a luminosity and a colour. Assuming a Kroupa initial mass function (IMF), we find: log [V80/(km s−1)] = (2.142 ± 0.004) + (0.278 ± 0.010)[log (M★/M⊙) − 10.10], where V80 is the rotation velocity measured at the radius R80 containing 80 per cent of the i-band galaxy light. This relation has an intrinsic Gaussian scatter dex and a measured scatter σmeas= 0.056 dex in log V80. For a fixed IMF, we find that the dynamical-to-stellar mass ratios within R80, (Mdyn/M★)(R80), decrease from approximately 10 to 3, as stellar mass increases from M★≈ 109 to 1011 M⊙. At a fixed stellar mass, (Mdyn/M★)(R80) increases with disc size, so that it correlates more tightly with stellar surface density than with stellar mass or disc size alone. We interpret the observed variation in (Mdyn/M★)(R80) with disc size as a reflection of the fact that disc size dictates the radius at which Mdyn/M★ is measured, and consequently, the fraction of the dark matter ‘seen’ by the gas at that radius. For the lowest M★ galaxies, we find a positive correlation between TFR residuals and disc sizes, indicating that the total density profile is dominated by dark matter on these scales. For the highest M★ galaxies, we find instead a weak negative correlation, indicating a larger contribution of stars to the total density profile. This change in the sense of the correlation (from positive to negative) is consistent with the decreasing trend in (Mdyn/M★)(R80) with stellar mass. In future work, we will use these results to study disc galaxy formation and evolution and perform a fair, statistical analysis of the dynamics and masses of a photometrically selected sample of disc galaxies.

 

Article title: Optical-to-virial velocity ratios of local disk galaxies from combined kinematics and galaxy-galaxy lensing

Authors: Reinabelle Reyes, Rachel Mandelbaum, James E. Gunn, Reiko Nakajima, Uros Seljak, Chris M. Hirata

Publication Title:  Monthly Notices of the Royal Astronomical Society 425(4), October 2011

 

Abstract:

In this paper, we measure the optical-to-virial velocity ratios Vopt/V200c of disk galaxies in the Sloan Digital Sky Survey (SDSS) at a mean redshift of = 0.07 and with stellar masses 10^9 M_sun < M_* < 10^11 M_sun. Vopt/V200c, the ratio of the circular velocity measured at the virial radius of the dark matter halo (\sim150 kpc) to that at the optical radius of the disk (\sim10 kpc), is a powerful observational constraint on disk galaxy formation. It links galaxies to their dark matter haloes dynamically and constrains the total mass profile of disk galaxies over an order of magnitude in length scale. For this measurement, we combine Vopt derived from the Tully-Fisher relation (TFR) from Reyes et al. with V200c derived from halo masses measured with galaxy-galaxy lensing. In anticipation of this combination, we use similarly-selected galaxy samples for both the lensing and TFR analysis. For three M_* bins with lensing-weighted mean stellar masses of 0.6, 2.7, and 6.5 x 10^10 M_sun, we find halo-to-stellar mass ratios M_vir/M_* = 41, 23, and 26, with 1-sigma statistical uncertainties of around 0.1 dex, and Vopt/V200c = 1.27\pm0.08, 1.39\pm0.06, 1.27\pm0.08 (1{\sigma}). Our results suggest that the dark matter and baryonic contributions to the mass within the optical radius are comparable, if the dark matter halo profile has not been significantly modified by baryons. The results obtained in this work will serve as inputs to and constraints on disk galaxy formation models, which will be explored in future work. Finally, we note that this paper presents a new and improved galaxy shape catalogue for weak lensing that covers the full SDSS DR7 footprint.

Full text link: https://tinyurl.com/y7qvyxov

Article title: Photometric redshift requirements for lens galaxies in galaxy-galaxy lensing analyses

Authors: Reiko Nakahima, R. Mandelbaum, U. Seljak, J.D. Cohn, Reinabelle Reyes, Richard J. Cool

Publication Title:  Monthly Notices of the Royal Astronomical Society 420(4), July  2011

 

Abstract:

Weak gravitational lensing is a valuable probe of galaxy formation and cosmology. Here we quantify the effects of using photometric redshifts (photo-z) in galaxy-galaxy lensing, for both sources and lenses, both for the immediate goal of using galaxies with photo-z as lenses in the Sloan Digital Sky Survey (SDSS) and as a demonstration of methodology for large, upcoming weak lensing surveys that will by necessity be dominated by lens samples with photo-z. We calculate the bias in the lensing mass calibration as well as consequences for absolute magnitude (i.e. k-corrections) and stellar mass estimates for a large sample of SDSS Data Release 8 (DR8) galaxies. The redshifts are obtained with the template-based photo-z code ZEBRA on the SDSS DR8 ugriz photometry. We assemble and characterize the calibration samples (˜9000 spectroscopic redshifts from four surveys) to obtain photometric redshift errors and lensing biases corresponding to our full SDSS DR8 lens and source catalogues. Our tests of the calibration sample also highlight the impact of observing conditions in the imaging survey when the spectroscopic calibration covers a small fraction of its footprint; atypical imaging conditions in calibration fields can lead to incorrect conclusions regarding the photo-z of the full survey. For the SDSS DR8 catalogue, we find σΔz/(1+z)= 0.096 and 0.113 for the lens and source catalogues, with flux limits of r= 21 and 21.8, respectively. The photo-z bias and scatter is a function of photo-z and template types, which we exploit to apply photo-z quality cuts. By using photo-z rather than spectroscopy for lenses, dim blue galaxies and L* galaxies up to z˜ 0.4 can be used as lenses, thus expanding into unexplored areas of parameter space. We also explore the systematic uncertainty in the lensing signal calibration when using source photo-z, and both lens and source photo-z; given the size of existing training samples, we can constrain the lensing signal calibration (and therefore the normalization of the surface mass density) to within 2 and 4 per cent, respectively.

Full text link: https://tinyurl.com/yct24suf

 

Article title: Calibrated Tully-fisher Relations For Improved Photometric Estimates Of Disk Rotation Velocities

Authors: Reinabelle Reyes, R. Mandelbaum, J.E. Gunn, J. Pizagno

Publication title: American Astronomical Society, AAS Meeting #217, id.430.06; Bulletin of the American Astronomical Society, Vol. 43, 2011

 

Abstract:

We present calibrated scaling relations (also referred to as Tully-Fisher relations or TFRs) between rotation velocity and photometric quantities-- absolute magnitude, stellar mass, and synthetic magnitude (a linear combination of absolute magnitude and color)-- of disk galaxies at z 0.1. First, we selected a parent disk sample of 170,000 galaxies from SDSS DR7, with redshifts between 0.02 and 0.10 and r band absolute magnitudes between -18.0 and -22.5. Then, we constructed a child disk sample of 189 galaxies that span the parameter space-- in absolute magnitude, color, and disk size-- covered by the parent sample, and for which we have obtained kinematic data. Long-slit spectroscopy were obtained from the Dual Imaging Spectrograph (DIS) at the Apache Point Observatory 3.5 m for 99 galaxies, and from Pizagno et al. (2007) for 95 galaxies (five have repeat observations). We find the best photometric estimator of disk rotation velocity to be a synthetic magnitude with a color correction that is consistent with the Bell et al. (2003) color-based stellar mass ratio. The improved rotation velocity estimates have a wide range of scientific applications, and in particular, in combination with weak lensing measurements, they enable us to constrain the ratio of optical-to-virial velocity in disk galaxies.

 

Article title: Confirmation of general relativity on large scales from weak lensing and galaxy velocities

Authors: Reinabelle Reyes, Rachel Mandelbaum, Uros Seljak, Tobias Baldauf, James E. Gunn, Lucas Lombriser, Robert E. Smith

Publication title: Nature 464 (7286) March 2010

 

Abstract: 

Although general relativity underlies modern cosmology, its applicability on cosmological length scales has yet to be stringently tested. Such a test has recently been proposed, using a quantity, E(G), that combines measures of large-scale gravitational lensing, galaxy clustering and structure growth rate. The combination is insensitive to 'galaxy bias' (the difference between the clustering of visible galaxies and invisible dark matter) and is thus robust to the uncertainty in this parameter. Modified theories of gravity generally predict values of E(G) different from the general relativistic prediction because, in these theories, the 'gravitational slip' (the difference between the two potentials that describe perturbations in the gravitational metric) is non-zero, which leads to changes in the growth of structure and the strength of the gravitational lensing effect. Here we report that E(G) = 0.39 +/- 0.06 on length scales of tens of megaparsecs, in agreement with the general relativistic prediction of E(G) approximately 0.4. The measured value excludes a model within the tensor-vector-scalar gravity theory, which modifies both Newtonian and Einstein gravity. However, the relatively large uncertainty still permits models within f(R) theory, which is an extension of general relativity. A fivefold decrease in uncertainty is needed to rule out these models.

Full text available: https://tinyurl.com/y7f5e744

 

Article title: Space Density of Optically Selected Type 2 Quasars

Authors: Reinabelle Reyes, Nadia L. Zakamska, Michael A. Strauss, Joshua Green, Julian H. Krolik, Yue Shen, Gordon T. Richards, Scott F. Anderson, Donald P. Schneider 

Publication title: The Astronomical Journal, 136 (6) : 2373, November 2008

 

Abstract: 

Type 2 quasars are luminous active galactic nuclei whose central regions are obscured by large amounts of gas and dust. In this paper, we present a catalog of type 2 quasars from the Sloan Digital Sky Survey, selected based on their optical emission lines. The catalog contains 887 objects with redshifts z < 0.83; this is 6 times larger than the previous version and is by far the largest sample of type 2 quasars in the literature. We derive the [O III]5007 luminosity function (LF) for 108.3 L ☉ < L [O III] < 1010 L ☉ (corresponding to intrinsic luminosities up to M[2500 Å] –28 mag or bolometric luminosities up to 4 × 1047 erg s–1). This LF provides robust lower limits to the actual space density of obscured quasars due to our selection criteria, the details of the spectroscopic target selection, and other effects. We derive the equivalent LF for the complete sample of type 1 (unobscured) quasars and determine the ratio of type 2 to type 1 quasar number densities. Our data constrain this ratio to be at least ~1.5:1 for 108.3 L ☉ < L [O III] < 109.5 L ☉ at z < 0.3, and at least ~1.2:1 for L [O III] ~ 1010 L ☉ at 0.3 < z < 0.83. Type 2 quasars are at least as abundant as type 1 quasars in the relatively nearby universe (z 0.8) for the highest luminosities.

Full text link: https://tinyurl.com/y73k448a

 

Article title: Erratum: "Space Density of optically selected type 2 quasars" (2008, AJ, 136, 2373)

Authors: Reinabelle Reyes, Nadia L. Zakamska, Michael A. Strauss, Joshua Green, Julian H. Krolik, Yue Shen, Gordon T. Richards, Scott F. Anderson, Donald P. Schneider 

Publication title: The Astronomical Journal 139 (3) : 1295, February 2010

 

Abstract: 

Figure 12 of the paper "Space Density of Optically Selected Type 2 Quasars" compares the obscured quasar fractions derived in our work with those of other studies. Unfortunately, some of the points from these other studies were shown incorrectly. Specifically, the results from X-ray data—Hasinger (2004; open circles) and Ueda et al. (2003; open squares)—which we had taken from Figure 16 of Hopkins et al. (2006), were affected by a luminosity conversion error, in the sense that the displayed luminosities for these data were too high by ~1 dex. With this erratum, we correct this problem and update the figure. The new version (Figure 12) shows more recent results from Hasinger (2008), in lieu of the Hasinger (2004) data points. These are based on data in the redshift range z = 0.2-3.2 (open circles) in that work. The best linear fit to these data (black dashed line) is consistent with that derived for the redshift slice z = 0.4-0.8, which overlaps with the highest redshift bin in our study, and is higher than that derived for redshifts smaller than 0.4 (corresponding to a shift of ~0.7 dex in luminosity). Figure 12 also shows estimates of the obscured quasar fraction derived from the ratio of IR to bolometric luminosities of an AGN sample at redshift z ~ 1 (Treister et al. 2008; filled triangles). Because the obscured quasar fractions derived from our analysis (colored arrows) are strict lower limits, there was already a hint in the previous version of Figure 12 that at high quasar luminosities, we find higher obscured quasar fractions than X-ray surveys. The correction and updates of Figure 12 strengthen this conclusion. At face value, our derived obscured quasar fractions are consistent with those from IR data (Treister et al. 2008; filled triangles). However, we find that they are significantly higher than those derived from X-ray surveys at , especially those from the recent analysis by Hasinger (2008). This comparison strongly suggests that optical selection successfully identifies a population of luminous obscured quasars that are missed by X-ray selection.

 

Article title: Test of Gravity on Large Scales with Weak Gravitational Lensing and Clustering Measurements of SDSS Luminous Red Galaxies

Authors: Reinabelle Reyes, R. Mandelbaum, U Seljak, J. Gunn, L. Lombriser

Publication title: American Astronomical Society, AAS Meeting #213, id.425.08; Bulletin of the American Astronomical Society, Vol. 41, p.253 January 2009 

 

Abstract: 

We perform a test of gravity on large scales (5-50 Mpc/h) using 70,000 luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS) DR7 with redshifts 0.16<z<0.47. Following Zhang et al. (2007), we define a quantity E_G-- a combination of measurements of weak gravitational lensing, galaxy peculiar velocities, and galaxy clustering-- that can discriminate between different theories of gravity and is largely independent of galaxy bias and sigma_8. In particular, E_G is sensitive to the relation between the spatial and temporal scalar perturbations in the space-time metric. While these two potentials are equivalent in concordance cosmology (GR+LCDM) in the absence of anisotropic stress, they are not equivalent in alternative theories of gravity in general, so that different models make different predictions for E_G. We find E_G=0.37±0.05 averaged over scales 5<R<50 Mpc/h, consistent with the prediction of LCDM, E_G = 0.375-0.425, for Omega_m=0.258±0.027. We also compare our measurements with preliminary predictions from modified gravity theories, including f(R), DGP, and TeVeS. This work serves as a proof of concept for the application of this test in future galaxy surveys such as LSST, for which a very high signal-to-noise measurement will be possible.

 

Article title: Improved optical mass tracer for galaxy clusters calibrated using weak lensing measurements

Authors: Reinabelle Reyes, Rachel Mandelbaum, Christopher Hirata, N.A Bahcall, Uros Seljak

Publication title: Monthly Notices of the Royal Astronomical Society 390(3) 1157-1169, November 2008

 

Abstract:

We develop an improved mass tracer for clusters of galaxies from optically observed parameters, and calibrate the mass relation using weak gravitational lensing measurements. We employ a sample of ∼13 000 optically selected clusters from the Sloan Digital Sky Survey (SDSS) maxBCG catalogue, with photometric redshifts in the range 0.1–0.3. The optical tracers we consider are cluster richness, cluster luminosity, luminosity of the brightest cluster galaxy (BCG) and combinations of these parameters. We measure the weak lensing signal around stacked clusters as a function of the various tracers, and use it to determine the tracer with the least amount of scatter. We further use the weak lensing data to calibrate the mass normalization. We find that the best mass estimator for massive clusters is a combination of cluster richness, N200, and the luminosity of the BCG, LBCG: , where is the observed mean BCG luminosity at a given richness. This improved mass tracer will enable the use of galaxy clusters as a more powerful tool for constraining cosmological parameters.

Full text link: https://tinyurl.com/yalzjs5j

 

Article title: Space Density Of Optically-Selected Type II Quasars From The SDSS

Authors: Reinabelle Reyes, Nadia L Zakamska, Michael A Strauss, Joshua Green, Julian H Krolik, Yue Shen, Gordon T Richards, Scott F Anderson, Donald P Schneider

Publication Title: Astronomical Journal 139(3) 1295-96, March 2010

 

Abstract: 

Type II quasars are luminous Active Galactic Nuclei (AGN) whose central regions are obscured by large amounts of gas and dust. In this poster, we present a catalog of 887 type II quasars with redshifts