Access to Astronomical Catalogues

← Click to display the menu
J/ApJ/806/95      A search for ultra-compact HVC counterparts      (Sand+, 2015)

A comprehensive archival search for counterparts to ultra-compact high-velocity clouds: five local volume dwarf galaxies. Sand D.J., Crnojevic D., Bennet P., Willman B., Hargis J., Strader J., Olszewski E., Tollerud E.J., Simon J.D., Caldwell N., Guhathakurta P., James B.L., Koposov S., McLeod B., Morrell N., Peacock M., Salinas R., Seth A.C., Stark D.P., Toloba E. <Astrophys. J., 806, 95 (2015)> =2015ApJ...806...95S (SIMBAD/NED BibCode)
ADC_Keywords: H I data ; Galaxies, optical ; Ultraviolet Keywords: galaxies: dwarf; galaxies: individual: (ALFALFA-Dw1, GALFA-Dw1, GALFA-Dw2, GALFA-Dw3, GALFA-Dw4); radio lines: galaxies Abstract: We report five Local Volume dwarf galaxies (two of which are presented here for the first time) uncovered during a comprehensive archival search for optical counterparts to ultra-compact high-velocity clouds (UCHVCs). The UCHVC population of HI clouds are thought to be candidate gas-rich, low-mass halos at the edge of the Local Group and beyond, but no comprehensive search for stellar counterparts to these systems has been presented. Careful visual inspection of all publicly available optical and ultraviolet imaging at the position of the UCHVCs revealed six blue, diffuse counterparts with a morphology consistent with a faint dwarf galaxy beyond the Local Group. Optical spectroscopy of all six candidate dwarf counterparts show that five have an Hα-derived velocity consistent with the coincident HI cloud, confirming their association; the sixth diffuse counterpart is likely a background object. The size and luminosity of the UCHVC dwarfs is consistent with other known Local Volume dwarf irregular galaxies. The gas fraction (MHI/Mstar) of the five dwarfs are generally consistent with that of dwarf irregular galaxies in the Local Volume, although ALFALFA-Dw1 (associated with ALFALFA UCHVC HVC274.68+74.70-123) has a very high MHI/Mstar∼40. Despite the heterogeneous nature of our search, we demonstrate that the current dwarf companions to UCHVCs are at the edge of detectability due to their low surface brightness, and that deeper searches are likely to find more stellar systems. If more sensitive searches do not reveal further stellar counterparts to UCHVCs, then the dearth of such systems around the Local Group may be in conflict with ΛCDM simulations. Description: We have searched all available optical and ultraviolet imaging archives for counterparts to the ultra-compact high-velocity clouds (UCHVCs; see section 2.1 and table 1). In addition to our archival search for counterparts to the UCHVCs, we have also acquired some supplementary imaging of select systems with the Magellan/Megacam in 2013 Jun 11 and 2014 Apr 26-27 and the APO/SPICAM in 2014 Nov 17 (see section 2.2). We have obtained spectroscopic observations for all six of the strong dwarf galaxy candidates identified in our search. ALFALFA-Dw1 (HVC274.68+74.70-123) was observed with the Inamori- Magellan Areal Camera and Spectrograph (IMACS) on the Magellan Baade telescope on 2014 June 17 (UT). GALFA-Dw1 (GALFA source 003.7+10.8+236), also known as Pisces A was observed on 2014 June 29 (UT) using the Goodman High-Throughput Spectrograph on the SOAR 4.1m telescope. GALFA-Dw2 (GALFA source 019.8+11.1+617), also known as Pisces B, was observed on 2014 October 21 (UT) with the Blue Channel Spectrograph on the MMT. GALFA-Dw3 (GALFA source 044.7+13.6+528) and GALFA-Dw4 (GALFA source 086.4+10.8+611) were observed with the 3.5m Astrophysical Research Consortium Telescope at APO on 2014 November 18 (UT) using the Dual Imaging Spectrograph (DIS). The faint, blue optical source coincident with GALFA 162.1+12.5+434 (see Figure 2) was observed on 2014 December 24 (UT) with the Blue Channel Spectrograph on the MMT. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 121 86 Summary of ultra-compact high-velocity cloud (UCHVC) archival search table3.dat 101 6 Spectroscopy log of dwarf galaxy candidates
See also: B/cfht : Log of CFHT Exposures (CADC, 1979-) J/AJ/146/145 : ALFALFA discovery of Leo P. IV. VI photometry (Mcquinn+, 2013) J/AJ/145/149 : ALFALFA discovery of Leo P. II. BVR photometry (Rhode+, 2013) J/ApJ/768/77 : Ultra-compact high velocity clouds from ALFALFA (Adams+, 2013) J/AJ/145/101 : Updated nearby galaxy catalog (Karachentsev+, 2013) J/ApJ/758/44 : The GALFA-HI compact cloud catalog (Saul+, 2012) J/ApJ/756/79 : Opt. photometry in 3 Local Group dwarf galaxies (Sand+, 2012) J/AJ/144/4 : Dwarf galaxies data in the Local Group (McConnachie+, 2012) J/AJ/142/170 : ALFALFA survey: the α.40 HI sources (Haynes+, 2011) J/AJ/139/315 : HI-selected galaxies in SDSS. Optical data (West+, 2010) J/AJ/133/2569 : Arecibo legacy fast ALFA survey III. (Giovanelli+, 2007) J/ApJ/655/144 : ACS Virgo Cluster Survey. XIII. (Mei+, 2007) J/AJ/130/873 : Properties of BQS objects in the SDSS DR3 area (Jester+, 2005) J/MNRAS/361/34 : HIPASS catalogue. III. (Doyle+, 2005) J/ApJ/623/181 : Compact high-velocity cloud photometry catalog (Siegel+, 2005) J/AJ/129/1311 : J-band photometry of ADBS Galaxies (Rosenberg+, 2005) J/AJ/123/873 : HIPASS high-velocity clouds (Putman+, 2002) J/ApJS/119/159 : Deep survey of HI-selected galaxies (Spitzak+, 1998) : SDSS-III home page Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Survey Survey (ALFALFA or GALFA-HI) 10- 25 A16 --- ID Ultra-compact high-velocity clouds (UCHVC) ID (see the "Nomenclature" section below) 27- 28 I2 h RAh [0/23] Hour of Right Ascension (J2000) 30- 31 I2 min RAm Minute of Right Ascension (J2000) 33- 36 F4.1 s RAs Second of Right Ascension (J2000) 38 A1 --- DE- [+] Sign of Declination (J2000) 39- 40 I2 deg DEd [4/36] Degree of Declination (J2000) 42- 43 I2 arcmin DEm Arcminute of Declination (J2000) 45- 46 I2 arcsec DEs Arcsecond of Declination (J2000) 48- 54 F7.2 km/s VLSR [-454/615] HI Local Standard of Rest velocity 56- 75 A20 --- Opt Optical Data 77- 79 A3 --- n_Opt Notes on Opt (1) 81- 87 A7 --- GALEX GALEX Data 89- 91 A3 --- n_GALEX Notes on GALEX (2) 93-121 A29 --- Comm Comments (3)
Note (1): Notes on Optical Data as follows: a = DSS images are listed only when it is the only option. d = Supplementary imaging; Section 2, Table 2 and the "Description" section above. e = CFHT (r,) texp=150s g = CFHT (i,) texp=476s h = CFHT (u,g,i) texp=(2400, 2760, 3240)s. i = CFHT (u,g,i,z) texp=(6402, 3170, 2055, 4400)s j = CFHT (r,) texp=420s k = CFHT (r,) texp=1600s l = CFHT (r,) texp=2260s m = CFHT (r,) texp=200s n = CFHT (g,) texp=1050s o = CFHT (u,g,r,i,z) texp=(6800,3100,3720,6000,7500)s p = CFHT (g,r,i,z) texp=(3170,4461,2055,4400)s q = CFHT (g,r,i,z) texp=(4800,1400,7500,4400)s s = CFHT (r,) texp=480s t = CFHT (r,) texp=240s u = CFHT (u,g,r,i) texp=(2800,5400,920,470)s Note (2): Notes on GALEX Data as follows: b = GALEX Allsky Imaging survey; texp∼100s c = GALEX Medium Imaging survey; texp∼1500s f = GALEX Guest Investigator data; NUV,FUV texp=1667s v = GALEX Guest Investigator data; NUV texp=1730s w = GALEX Guest Investigator data; FUV,NUV texp=1655,1655s x = GALEX Guest Investigator data; NUV texp=1650s y = GALEX Guest Investigator data; NUV texp=1690s z = GALEX Guest Investigator data; NUV texp=1605s aa = GALEX Guest Investigator data; NUV texp=1909s ab = GALEX Guest Investigator data; FUV, NUV texp=1500,1500s ac GALEX Guest Investigator data; FUV, NUV texp=5057,5057s Note (3): Notes on Comments: B14 = Fields with deep imaging reported by Bellazzini et al. (2015A&A...575A.126B). None of these found dwarf counterparts, besides ALFALFA-Dw1. (*) = Candidate diffuse dwarf galaxy at UCHVC position. GALFA-Dw1 and GALFA-Dw2 are Pisces A and Pisces B, as reported by Tollerud et al. (2015ApJ...798L..21T). ALFALFA-Dw1 is SECCO 1 as reported by Bellazzini et al. (2015ApJ...800L..15B).
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 15 A15 --- Target Target designation 17- 21 A5 --- Survey ("HVC" for ALFALFA or "GALFA" for GALFA-HI) 23- 38 A16 --- ID UCHVC ID 40- 53 A14 --- Tel Telescope/Instrument 55- 65 A11 "YYYY/MMM/DD" Date Observation date 67 I1 --- Exp1 Exposure time 1 68 A1 --- --- [x] 69- 72 I4 --- Exp2 Exposure time 2 74- 77 I4 km/s Vlsr [-114/5730] Hα LSR velocity 79- 81 I3 km/s e_Vlsr [8/200] Vlsr uncertainty 83-101 A19 --- Notes Notes
Nomenclature Notes: GALFA-HI sources are <[SPG2012] DDD.d+DD.d+VVV> in Simbad while ALFALFA sources are <HVC LLL.l+BB.b+VVV> in Simbad. History: From electronic version of the journal * 16-Nov-2015: Insert into VizieR * 24-Feb-2017: Misprint corrected in table 1: ID 087.35-39.78-434 (ALFALFA) corrected for 087.35-39.78-454
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 12-Oct-2015
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service

© Unistra/CNRS