In the catalog of M-dwarfs presented in Holwerda et al. (2014, H14 hereafter), there is an issue with the conversion from celestial coordinates to Galactic ones, done with PYEPHEM a wrapper around a trusted and vetted library ephermis. Here we present the corrected coordinates (using ASTROPY) and distances based on AB magnitudes. We have amended the tables and figures accordingly. The relation between vertical scale-height (z0) and M- dwarf subtype found in H14 is no longer present. We find a scale-height of 600 pc for all types, in part due to the presence of a second Galactic structural component

Andersen, M.

Bouwens, R. J.

Bradley, L.

Clarkson, W.

De Marchi, G.

Holwerda, Benne W.

Pirzkal, N.

Ryan, R.

Sahu, K.

Stiavelli, M.

Trenti, M.

van der Vlugt, D.

van Vledder, I.

English

University of Louisville

University of Louisville ThinkIR: The University of Louisville's Institutional Repository Faculty Scholarship 7-2016 Erratum: “Milky Way red dwarfs in the Borg survey; galactic scale-height and the distribution of dwarfs stars in WFC3 imaging". Benne W. Holwerda University of Louisville M. Trenti University of Melbourne W. Clarkson University of Michigan - Dearborn K. Sahu Space Telescope Science Institute L. Bradley Space Telescope Science Institute See next page for additional authors Follow this and additional works at: https://ir.library.louisville.edu/faculty  Part of the Astrophysics and Astronomy Commons Original Publication Information Holwerda, B. W., et al. "Erratum: 'Milky Way Red Dwarfs in the Borg Survey; Galactic Scale-Height and the Distribution of Dwarfs Stars in WFC3 Imaging." 2016. The Astrophysical Journal 825(1): 5 pp. This Article is brought to you for free and open access by ThinkIR: The University of Louisville's Institutional Repository. It has been accepted for inclusion in Faculty Scholarship by an authorized administrator of ThinkIR: The University of Louisville's Institutional Repository. For more information, please contact thinkir@louisville.edu. Authors Benne W. Holwerda, M. Trenti, W. Clarkson, K. Sahu, L. Bradley, M. Stiavelli, N. Pirzkal, G. De Marchi, M. Andersen, R. J. Bouwens, R. Ryan, I. van Vledder, and D. van der Vlugt This article is available at ThinkIR: The University of Louisville's Institutional Repository: https://ir.library.louisville.edu/faculty/166 ERRATUM: “MILKY WAY RED DWARFS IN THE BORG SURVEY; GALACTIC SCALE-HEIGHT AND THEDISTRIBUTION OF DWARFS STARS IN WFC3 IMAGING” (2014, ApJ, 788, 77)B. W. Holwerda1,2,7,8, M. Trenti3, W. Clarkson4, K. Sahu5, L. Bradley5, M. Stiavelli5, N. Pirzkal5, G. De Marchi2,M. Andersen6, R. Bouwens1, R. Ryan5, I. van Vledder1, and D. van der Vlugt11 Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands; holwerda@strw.leidenuniv.nl2 European Space Agency, ESA-ESTEC, Keplerlaan 1, 2200 AG Noordwijk, The Netherlands3 School of Physics, University of Melbourne, VIC 3010, Australia4 Department of Natural Sciences College of Arts, Sciences and Letters, University of Michigan-Dearborn 4901 Evergreen Road, Dearborn, MI:48128, USA5 Space Telescope Science Institute, Baltimore, MD 21218, USA6 UJF-Grenoble 1/CNRS-INSU, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041, FranceReceived 2015 October 20; revised 2016 February 3; accepted 2016 February 3; published 2016 July 5ABSTRACTIn the catalog of M-dwarfs presented in Holwerda et al. (2014, H14 hereafter), there is an issue with the conversion fromcelestial coordinates to Galactic ones, done with PYEPHEM a wrapper around a trusted and vetted library ephermis. Herewe present the corrected coordinates (using ASTROPY) and distances based on AB magnitudes. We have amended thetables and figures accordingly. The relation between vertical scale-height (z0) and M- dwarf subtype found in H14 is nolonger present. We find a scale-height of 600 pc for all types, in part due to the presence of a second Galactic structuralcomponent.1. MAPPING THE M-DWARF DISTRIBUTIONWe re-computed the Galactic coordinates for the BoRG fields using the ASTROPY package (Astropy Collaboration et al. 2013) andthe number of M-dwarfs in each, shown in the new Figure 22. The new values for all identified M-dwarfs are listed in Table 14. Toestimate the distances to each M-dwarf, we compute the distance modulus from the inferred sub-type (and hence absolute magnitude)and the apparent magnitude in JF W125 from Hawley et al. (2002), converted from Vega magnitudes to AB. We compute the Galacticradius and height above the plane for all M-dwarfs, based on their Galactic longitude, latitude and the inferred photometric distances,assuming the position of the Sun 27 pc. above the plane and 8.5 kpc from the Galactic center.The net difference with Holwerda et al. (2014, H14 hereafter) is that the vertical distribution observed for these M-dwarfs is muchcloser to the exponential drop-off one would expect for fields out of the plane of the Galaxy.Figure 24 shows the vertical distribution of M-dwarfs color-coded by their Galactocentric radius. There is a clear disk componentwith all the M-dwarfs are ∼6–10 kpc from the center of the Milky Way and another component which shows a gradient with radiusand is well above the plane of the disk. We now know this component to be the Halo part of the vertical distribution (van Vledderet al. 2016) but it is sometimes treated as the thick disk by other authors (e.g., Ryan & Reid 2016). This second component ismuch clearer in the corrected Galactic positions compared to H14. The majority of stars close to the plane of the disk are ∼8 kpc fromthe center of the Galaxy. This is because the majority of BoRG fields are pointing out of the disk at an angle away from theGalactic Center (to avoid confusion with Galactic Objects) and thus probe the vertical extent of the disk close to the position ofthe Sun.We assume there is no need to correct the densities in this part of the disk for the exponential decline with radius. Figure 24 doesshow a radial dependence of the outer parts of the vertical distribution on the radius. Our assumption is that the scale-height does notchange significantly with radius, which is observed in external galaxies seen edge-on (Comerón et al. 2011a, 2011a, 2011c, Streichet al. 2016 in preparation).We assume that the Galactic disk has the following parametric shape:⎛⎝⎜⎞⎠⎟r r= - ´R z R h sechzz, exp2, 1020( ) ( ) ( )where ρ(R, z) is the dwarf number density in a point in the disk, ρ0 is the central number density, R is Galactocentric radius, h is thescale-length, z is height above the plane, and z0 is the exponential scale-height of the disk. Figure 25 shows how the later-typeM-dwarfs (M4-8) in the BoRG fields are concentrated in the thin disk and the earlier types (M0-3) probe both thin disk and the othercomponent. We fit the sech2 distribution to each photometric subtype, as well as early-, late- and all-types of M-dwarfs, summarizedin the new Table 10 and the new Figures 26 and 27.Figures 26 and 27 are significantly different from the versions in H14 in two ways: the relation between vertical scale-height (z0)and M- dwarf subtype found in H14 is no longer present in Figure 27. Second, the densities inferred are much closer to the local(<20 pc of the Sun) Reid et al. (2004) and Cruz et al. (2007) values (Figure 26). We note there is an offset of ∼0.1 dex between ourcentral density and the one implied by Reid et al. The likely culprit is the additional numbers of M-dwarfs in the secondaryThe Astrophysical Journal, 825:82 (5pp), 2016 July 1 doi:10.3847/0004-637X/825/1/82© 2016. The American Astronomical Society. All rights reserved.7 twitter:benneholwerda.8 Research Fellow.1Figure 22. The Aitoff projection of the distribution of BoRG fields with thesurface density of M-dwarfs of all types indicated. One field, borg_1230+0750(star) stands out with 22 M-dwarfs (∼5 stars arcmin−2). We discardborg_1815-3244 (black circle) for its low latitudes and line-of-sight throughthe plane of the disk and close of the center of the bulge.Figure 24. The volume density of M-dwarfs as a function as height above theplane of the Milky Way disk. The volume densities were normalized with ascale-length of 2.6 kpc and a depth of 1pc at each star’s position. Points arecolor-coded by the inferred Galactic radius. The majority of M-dwarfs arefound close to the plane of the disk.Figure 25. The volume density of M-dwarfs as a function as height above theplane of the Milky Way disk. Points and fits are color-coded by the M-dwarfsub-type.Table 10The Vertical Profile Fits to The Full Sample of Identified M-dwarfsM-type ρ0 z0(◦) (#/pc3) (kpc)0 0.02 0.67±0.731 0.19 0.84±0.892 0.06 0.80±1.313 0.60 0.61±12.364 0.14 1.04±0.675 0.77 0.67±0.746 2.49 1.03±5.427 K K8 181.04 −0.01±0.02Note. Values are Scaled so to be Compatible with Exponential Fits to TheGalactic Profiles (ρ0/4 and z0/2).Figure 26. The in-plane central density—the number of M-dwarfs belonging tothe disk at the center of the Milky Way–for the best fit to the verticaldistribution of M-dwarfs as a function of the M-dwarf subtype. The blackcircles are the values from Reid et al. (2008) for the immediate Solarneighborhood (<20 pc), renormalized to the center of the Milky Way.Figure 27. The scale-height (z0/2) of the best vertical fit as a function of theM-dwarf subtype. Dashed lines are the uncertainty in the fit. A constant valueof 600 pc would be consistent with most of these fits. This is ∼2× greater thanexpected from previous work.2The Astrophysical Journal, 825:82 (5pp), 2016 July 1 Holwerda et al.Table 14The 274 M-dwarfs Identified in BoRGID R.A. Decl. l b mF M098 mF W125 mF W125 mF W606 Mtype modulus dist Height Radius Volume Areaborg_0110-0224.551.017.501759 −2.418265 133.918256 −64.893095 23.82±0.04 23.46±0.02 23.28±0.03 25.17±0.09 2.04±0.32 16.48 19.74 14.25 16.88±1.85 228.43 10.88borg_0110-0224.719.017.503586 −2.415663 133.921454 −64.890220 24.33±0.05 23.97±0.03 23.87±0.04 25.83±0.14 2.56±0.50 16.73 22.16 15.99 17.90±2.73 287.73 10.88borg_0110-0224.820.017.528020 −2.411389 133.976421 −64.881854 19.68±0.00 19.51±0.00 19.45±0.00 22.77±0.01 7.30±0.04 8.59 0.52 0.40 8.72±0.01 0.16 10.88borg_0110-0224.1016.017.553100 −2.408888 134.033565 −64.875102 24.54±0.09 23.90±0.04 23.72±0.05 25.39±0.13 1.30±0.46 17.18 27.26 19.63 20.08±3.83 435.66 10.88borg_0110-0224.1414.017.559120 −2.400783 134.044244 −64.866085 24.08±0.06 23.71±0.06 23.44±0.04 24.40±0.05 −1.43±0.27 17.26 28.31 20.37 20.52±687.31 469.66 10.883TheAstrophysicalJournal,825:82(5pp),2016July1Holwerdaetal.Table 15The 1 T-Dwarfs Identified in BoRGID R.A. Decl. l b mF M098 mF W125 mF W125 mF W606borg_0540-6409.1929.0 84.862502 −64.152446 84.862502 −64.152446 22.9±0.0 21.9±0.0 22.2±0.0 21.5±0.0Table 16The 30 L-Dwarfs Identified in BoRGID R.A. Decl. l b mF M098 mF W125 mF W125 mF W606borg_0110-0224.1010.0 17.537240 −2.409470 17.537240 −2.409470 24.7±0.1 23.7±0.0 23.5±0.0 25.3±0.1borg_0439-5317.882.0 69.836642 −53.263207 69.836642 −53.263207 24.0±0.0 22.7±0.0 22.2±0.0 24.8±0.9borg_0540-6409.2993.0 84.876906 −64.132531 84.876906 −64.132531 25.0±0.1 23.8±0.0 23.4±0.0 26.8±0.6borg_0751+2917.567.0 117.684321 29.285619 117.684321 29.285619 19.5±0.0 17.8±0.0 17.6±0.0 19.6±0.0borg_0808+3946.457.0 122.094091 39.759095 122.094091 39.759095 25.0±0.1 23.9±0.0 23.5±0.0 26.9±0.6borg_0819+4911.264.0 124.831743 49.175806 124.831743 49.175806 23.9±0.0 22.8±0.0 22.4±0.0 27.9±1.6borg_0906+0255.462.0 136.409407 2.923645 136.409407 2.923645 24.4±0.0 23.3±0.0 22.8±0.0 27.6±0.8borg_0909+0002.748.0 137.292821 −0.012257 137.292821 −0.012257 24.5±0.1 23.2±0.0 22.8±0.3 26.6±0.4borg_0914+2822.673.0 138.558022 28.364206 138.558022 28.364206 24.8±0.1 23.5±0.0 23.1±0.0 26.3±0.3borg_0926+4426.581.0 141.355847 44.425445 141.355847 44.425445 24.3±0.0 23.1±0.0 22.6±0.0 25.2±0.9borg_1103-2330.623.0 165.819910 −23.506010 165.819910 −23.506010 23.9±0.1 22.9±0.0 22.5±0.0 25.7±0.2borg_1111+5545.1125.0 167.747157 55.771759 167.747157 55.771759 23.6±0.0 22.5±0.0 22.1±0.0 26.6±0.3borg_1153+0056.247.0 178.200215 0.922794 178.200215 0.922794 23.9±0.0 22.9±0.0 22.4±0.0 26.2±0.3borg_1230+0750.2419.0 187.471709 7.820117 187.471709 7.820117 23.9±0.1 22.8±0.0 22.3±0.0 26.2±0.3borg_1301+0000.1067.0 195.326828 0.013297 195.326828 0.013297 23.5±0.1 22.2±0.0 21.8±0.0 24.3±0.9borg_1337+0028.1117.0 204.205278 −0.445870 204.205278 −0.445870 24.3±0.2 23.1±0.0 22.7±0.0 25.3±0.9borg_1524+0954.24.0 231.044740 9.885957 231.044740 9.885957 24.9±0.1 23.0±0.1 22.8±0.1 25.3±1.0borg_1632+3733.65.0 248.069017 37.540353 248.069017 37.540353 24.5±0.0 23.3±0.0 22.9±0.0 28.5±2.1borg_1632+3733.349.0 248.080963 37.550065 248.080963 37.550065 23.5±0.0 22.4±0.0 22.0±0.1 27.1±1.4borg_1632+3733.1325.0 248.076265 37.572819 248.076265 37.572819 24.3±0.0 23.0±0.1 22.5±0.0 26.7±0.5borg_2132+1004.284.0 323.058751 10.068991 323.058751 10.068991 16.8±0.0 15.0±0.0 14.7±0.0 17.2±0.9borg_2132+1004.332.0 323.060235 10.059801 323.060235 10.059801 21.2±0.0 19.9±0.0 19.7±0.0 22.2±0.9borg_2155-4411.227.0 328.831076 −44.185153 328.831076 −44.185153 23.5±0.0 22.5±0.0 22.2±0.0 24.8±0.9borg_2155-4411.974.0 328.809893 −44.164189 328.809893 −44.164189 24.3±0.0 23.0±0.0 22.5±0.0 25.1±0.9borg_2351-4332.1314.0 357.668728 −43.514053 357.668728 −43.514053 25.2±0.1 23.9±0.0 23.5±0.0 26.0±0.9borg_0456-2203.920.0 73.945566 −22.049396 73.945566 −22.049396 24.6±0.1 23.4±0.0 23.2±0.0 24.4±0.0borg_1059+0519.644.0 164.717943 5.301323 164.717943 5.301323 24.4±0.0 23.1±0.0 22.6±0.0 26.5±0.3borg_1118-1858.1915.0 169.392755 −18.972497 169.392755 −18.972497 24.8±0.0 23.8±0.0 23.3±0.0 26.1±0.1borg_1459+7146.1298.0 224.751450 71.780685 224.751450 71.780685 24.8±0.2 23.5±0.0 23.1±0.0 25.7±0.1borg_2132-1202.6461.0 322.941469 −12.021619 322.941469 −12.021619 24.6±0.1 23.4±0.0 23.0±0.0 26.5±0.4Figure 28. The distribution of BoRG fields with the number of L-dwarfs indicated. Other symbols identical to Figure 22.4The Astrophysical Journal, 825:82 (5pp), 2016 July 1 Holwerda et al.component well above the plane of the disk, i.e., we are including the density of Halo stars in our disk fit. A 0.1 dex offset suggest oforder 10% of the stars in are, in fact, Halo stars (see also van Vledder et al. 2016).The values in Figure 27 and Table 10 are still too high to be consistent with previous work on the vertical scale of stars in the thindisk. The vertical sech2 profile does not describe the density distribution well above ∼500 pc and this new distributions highlights theneed to include another component well above and in addition to the disk.For completeness, we include Figure 28 which shows the surface density of L-dwarfs selected by our morphology and colorcriteria.2. CONCLUSIONSThe majority of conclusions for Holwerda et al. (2014) remain the same, only the last two change:1. The secondary component visible in the vertical distribution of M-dwarfs is likely the Halo and not the thick disk of the MilkyWay (Figures 24 and 25).2. A naive, single-component fit of the vertical distribution of M-dwarfs shows no dependence on M-dwarf subtype and a scale-height for all M-dwarf subtypes that is still too high to be consistent with previous measures of the scale-height: z0∼600 pc,(Figure 27), a result of the second structural component.The authors would like to thank the referee, K. Cruz for her help with the erratum. This research made use of Astropy, acommunity-developed core Python package for Astronomy (Astropy Collaboration et al. 2013). This research made use ofmatplotlib, a Python library for publication quality graphics (Hunter 2007). PyRAF is a product of the Space Telescope ScienceInstitute, which is operated by AURA for NASA. This research made use of SciPy (Jones et al. 2001).REFERENCESAstropy Collaboration, Robitaille, T. P., Tollerud, E. J., et al. 2013, A&A,558, A33Comerón, S., Elmegreen, B. G., Knapen, J. H., et al. 2011b, ApJ, 738, L17Comerón, S., Elmegreen, B. G., Knapen, J. H., et al. 2011c, ApJ, 741, 28Comerón, S., Knapen, J. H., Sheth, K., et al. 2011c, ApJ, 729, 18Cruz, K. L., Reid, I. N., Kirkpatrick, J. D., et al. 2007, AJ, 133, 439Hawley, S. L., Covey, K. R., Knapp, G. R., et al. 2002, AJ, 123, 3409Holwerda, B. W., Trenti, M., Clarkson, W., et al. 2014, ApJ, 788, 77Hunter, J. D. 2007, Computing In Science & Engineering, 9, 90Jones, E., Oliphant, T., Peterson, P., et al. 2001, SciPy: Open source scientifictools for PythonReid, I. N., Cruz, K. L., Allen, P., et al. 2004, AJ, 128, 463Reid, I. N., Cruz, K. L., Kirkpatrick, J. D., et al. 2008, AJ, 136, 1290Ryan, R. E., Jr., & Reid, I. N. 2016, AJ, 151, 92van Vledder, Is., van der Vlugt, D., Holwerda, B. W., Kenworthy, M. A.,Bouwens, R. J., & Trenti, M. 2016, MNRAS, 458, 4255The Astrophysical Journal, 825:82 (5pp), 2016 July 1 Holwerda et al.

Erratum: “Milky Way red dwarfs in the Borg survey; galactic scale-height and the distribution of dwarfs stars in WFC3 imaging .

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Erratum: “Milky Way red dwarfs in the Borg survey; galactic scale-height and the distribution of dwarfs stars in WFC3 imaging .

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