Publications by Dimitra Rigopoulou


A multi-wavelength view of the star formation activity at z ∼ 3

Astrophysical Journal 714 (2010) 1740-1745

GE Magdis, D Elbaz, E Daddi, GE Morrison, M Dickinson, D Rigopoulou, R Gobat, HS Hwang

We present a multi-wavelength, UV-to-radio analysis for a sample of massive (M * ∼ 1010 M ⊙) IRAC- and MIPS 24 μm detected Lyman break galaxies (LBGs) with spectroscopic redshifts z 3 in the GOODS-North field. For LBGs without individual 24 μm detections, we employ stacking techniques at 24 μm, 1.1mm, and 1.4GHz to construct the average UV-to-radio spectral energy distribution and find it to be consistent with that of a luminous infrared galaxy with L IR = 4.5 +1.1-2.3 × 1011 L ⊙ and a specific star formation rate of 4.3 Gyr-1 that corresponds to a mass doubling time 230 Myr. On the other hand, when considering the 24 μm detected LBGs we find among them galaxies with L IR>10 12 L ⊙, indicating that the space density of z 3 UV-selected ultra-luminous infrared galaxies (ULIRGs) is (1.5 0.5) × 10-5 Mpc-3. We compare measurements of star formation rates from data at different wavelengths and find that there is tight correlation (Kendall's τ>99.7%) and excellent agreement between the values derived from dust-corrected UV, mid-IR, millimeter, and radio data for the whole range of L IR up to L IR 1013 L ⊙. This range is greater than that for which the correlation is known to hold at z ∼ 2, possibly due to the lack of significant contribution from polycyclic aromatic hydrocarbons to the 24 μm flux at z ∼ 3. The fact that this agreement is observed for galaxies with L IR> 1012 L ⊙ suggests that star formation in UV-selected ULIRGs, as well as the bulk of star formation activity at this redshift, is not embedded in optically thick regions as seen in local ULIRGs and submillimeter-selected galaxies at z = 2. © 2010 The American Astronomical Society. All rights reserved.


The Herschel-SPIRE instrument and its in-flight performance

ASTRONOMY & ASTROPHYSICS 518 (2010) ARTN L3

MJ Griffin, A Abergel, A Abreu, PAR Ade, P Andre, J-L Augueres, T Babbedge, Y Bae, T Baillie, J-P Baluteau, MJ Barlow, G Bendo, D Benielli, JJ Bock, P Bonhomme, D Brisbin, C Brockley-Blatt, M Caldwell, C Cara, N Castro-Rodriguez, R Cerulli, P Chanial, S Chen, E Clark, DL Clements, L Clerc, J Coker, D Communal, L Conversi, P Cox, D Crumb, C Cunningham, F Daly, GR Davis, P De Antoni, J Delderfield, N Devin, A Di Giorgio, I Didschuns, K Dohlen, M Donati, A Dowell, CD Dowell, L Duband, L Dumaye, RJ Emery, M Ferlet, D Ferrand, J Fontignie, M Fox, A Franceschini, M Frerking, T Fulton, J Garcia, R Gastaud, WK Gear, J Glenn, A Goizel, DK Griffin, T Grundy, S Guest, L Guillemet, PC Hargrave, M Harwit, P Hastings, E Hatziminaoglou, M Herman, B Hinde, V Hristov, M Huang, P Imhof, KJ Isaak, U Israelsson, RJ Ivison, D Jennings, B Kiernan, KJ King, AE Lange, W Latter, G Laurent, P Laurent, SJ Leeks, E Lellouch, L Levenson, B Li, J Li, J Lilienthal, T Lim, SJ Liu, N Lu, S Madden, G Mainetti, P Marliani, D McKay, K Mercier, S Molinari, H Morris, H Moseley, J Mulder, M Mur, DA Naylor, H Nguyen, B O'Halloran, S Oliver, G Olofsson, H-G Olofsson, R Orfei, MJ Page, I Pain, P Panuzzo, A Papageorgiou, G Parks, P Parr-Burman, A Pearce, C Pearson, I Perez-Fournon, F Pinsard, G Pisano, J Podosek, M Pohlen, ET Polehampton, D Pouliquen, D Rigopoulou, D Rizzo, IG Roseboom, H Roussel, M Rowan-Robinson, B Rownd, P Saraceno, M Sauvage, R Savage, G Savini, E Sawyer, C Scharmberg, D Schmitt, N Schneider, B Schulz, A Schwartz, R Shafer, DL Shupe, B Sibthorpe, S Sidher, A Smith, AJ Smith, D Smith, L Spencer, B Stobie, R Sudiwala, K Sukhatme, C Surace, JA Stevens, BM Swinyard, M Trichas, T Tourette, H Triou, S Tseng, C Tucker, A Turner, M Vaccari, I Valtchanov, L Vigroux, E Virique, G Voellmer, H Walker, R Ward, T Waskett, M Weilert, R Wesson, GJ White, N Whitehouse, CD Wilson, B Winter, AL Woodcraft, GS Wright, CK Xu, A Zavagno, M Zemcov, L Zhang, E Zonca


HerMES: The SPIRE confusion limit

ASTRONOMY & ASTROPHYSICS 518 (2010) ARTN L5

HT Nguyen, B Schulz, L Levenson, A Amblard, V Arumugam, H Aussel, T Babbedge, A Blain, J Bock, A Boselli, V Buat, N Castro-Rodriguez, A Cava, P Chanial, E Chapin, DL Clements, A Conley, L Conversi, A Cooray, CD Dowell, E Dwek, S Eales, D Elbaz, M Fox, A Franceschini, W Gear, J Glenn, M Griffin, M Halpern, E Hatziminaoglou, E Ibar, K Isaak, RJ Ivison, G Lagache, N Lu, S Madden, B Maffei, G Mainetti, L Marchetti, G Marsden, J Marshall, B O'Halloran, SJ Oliver, A Omont, MJ Page, P Panuzzo, A Papageorgiou, CP Pearson, I Perez Fournon, M Pohlen, N Rangwala, D Rigopoulou, D Rizzo, IG Roseboom, M Rowan-Robinson, D Scott, N Seymour, DL Shupe, AJ Smith, JA Stevens, M Symeonidis, M Trichas, KE Tugwell, M Vaccari, I Valtchanov, L Vigroux, L Wang, R Ward, D Wiebe, G Wright, CK Xu, M Zemcov


Herschel-ATLAS: Evolution of the 250 mu m luminosity function out to z = 0.5

ASTRONOMY & ASTROPHYSICS 518 (2010) ARTN L10

S Dye, L Dunne, S Eales, DJB Smith, A Amblard, R Auld, M Baes, IK Baldry, S Bamford, AW Blain, DG Bonfield, M Bremer, D Burgarella, S Buttiglione, E Cameron, A Cava, DL Clements, A Cooray, S Croom, A Dariush, G de Zotti, S Driver, JS Dunlop, D Frayer, J Fritz, JP Gardner, HL Gomez, J Gonzalez-Nuevo, D Herranz, D Hill, A Hopkins, E Ibar, RJ Ivison, MJ Jarvis, DH Jones, L Kelvin, G Lagache, L Leeuw, J Liske, M Lopez-Caniego, J Loveday, S Maddox, MJ Michalowski, M Negrello, P Norberg, MJ Page, H Parkinson, E Pascale, JA Peacock, M Pohlen, C Popescu, M Prescott, D Rigopoulou, A Robotham, E Rigby, G Rodighiero, S Samui, D Scott, S Serjeant, R Sharp, B Sibthorpe, P Temi, MA Thompson, R Tuffs, I Valtchanov, PP van der Werf, E van Kampen, A Verma


The HerMES SPIRE submillimeter local luminosity function

ASTRONOMY & ASTROPHYSICS 518 (2010) ARTN L20

M Vaccari, L Marchetti, A Franceschini, B Altieri, A Amblard, V Arumugam, R Auld, H Aussel, T Babbedge, A Blain, J Bock, A Boselli, V Buat, D Burgarella, N Castro-Rodriguez, A Cava, P Chanial, DL Clements, A Conley, L Conversi, A Cooray, CD Dowell, E Dwek, S Dye, S Eales, D Elbaz, D Farrah, M Fox, W Gear, J Glenn, EAG Solares, M Griffin, M Halpern, E Hatziminaoglou, J Huang, E Ibar, K Isaak, RJ Ivison, G Lagache, L Levenson, N Lu, S Madden, B Maffei, G Mainetti, AMJ Mortier, HT Nguyen, B O'Halloran, SJ Oliver, A Omont, MJ Page, P Panuzzo, A Papageorgiou, CP Pearson, I Perez-Fournon, M Pohlen, JI Rawlings, G Raymond, D Rigopoulou, D Rizzo, G Rodighiero, IG Roseboom, M Rowan-Robinson, M Sanchez Portal, B Schulz, D Scott, N Seymour, DL Shupe, AJ Smith, JA Stevens, M Symeonidis, M Trichas, KE Tugwell, E Valiante, I Valtchanov, L Vigroux, L Wang, R Ward, G Wright, CK Xu, M Zemcov


HerMES: SPIRE galaxy number counts at 250, 350, and 500 mu m

ASTRONOMY & ASTROPHYSICS 518 (2010) ARTN L21

SJ Oliver, L Wang, AJ Smith, B Altieri, A Amblard, V Arumugam, R Auld, H Aussel, T Babbedge, A Blain, J Bock, A Boselli, V Buat, D Burgarella, N Castro-Rodriguez, A Cava, P Chanial, DL Clements, A Conley, L Conversi, A Cooray, CD Dowell, E Dwek, S Eales, D Elbaz, M Fox, A Franceschini, W Gear, J Glenn, M Griffin, M Halpern, E Hatziminaoglou, E Ibar, K Isaak, RJ Ivison, G Lagache, L Levenson, N Lu, S Madden, B Maffei, G Mainetti, L Marchetti, K Mitchell-Wynne, AMJ Mortier, HT Nguyen, B O'Halloran, A Omont, MJ Page, P Panuzzo, A Papageorgiou, CP Pearson, I Perez-Fournon, M Pohlen, JI Rawlings, G Raymond, D Rigopoulou, D Rizzo, IG Roseboom, M Rowan-Robinson, M Sanchez Portal, R Savage, B Schulz, D Scott, N Seymour, DL Shupe, JA Stevens, M Symeonidis, M Trichas, KE Tugwell, M Vaccari, E Valiante, I Valtchanov, JD Vieira, L Vigroux, R Ward, G Wright, CK Xu, M Zemcov


First results from HerMES on the evolution of the submillimetre luminosity function

ASTRONOMY & ASTROPHYSICS 518 (2010) ARTN L23

SA Eales, G Raymond, IG Roseboom, B Altieri, A Amblard, V Arumugam, R Auld, H Aussel, T Babbedge, A Blain, J Bock, A Boselli, D Brisbin, V Buat, D Burgarella, N Castro-Rodriguez, A Cava, P Chanial, DL Clements, A Conley, L Conversi, A Cooray, CD Dowell, E Dwek, S Dye, D Elbaz, D Farrah, M Fox, A Franceschini, W Gear, J Glenn, EAG Solares, M Griffin, M Harwit, E Hatziminaoglou, J Huang, E Ibar, K Isaak, RJ Ivison, G Lagache, L Levenson, CJ Lonsdale, N Lu, S Madden, B Maffei, G Mainetti, L Marchetti, GE Morrison, AMJ Mortier, HT Nguyen, B O'Halloran, SJ Oliver, A Omont, FN Owen, MJ Page, M Pannella, P Panuzzo, A Papageorgiou, CP Pearson, I Perez-Fournon, M Pohlen, JI Rawlings, D Rigopoulou, D Rizzo, M Rowan-Robinson, M Sanchez Portal, B Schulz, D Scott, N Seymour, DL Shupe, AJ Smith, JA Stevens, V Strazzullo, M Symeonidis, M Trichas, KE Tugwell, M Vaccari, I Valtchanov, L Vigroux, L Wang, R Ward, G Wright, CK Xu, M Zemcov


HerMES: The submillimeter spectral energy distributions of Herschel/SPIRE-detected galaxies

ASTRONOMY & ASTROPHYSICS 518 (2010) ARTN L32

B Schulz, CP Pearson, DL Clements, B Altieri, A Amblard, V Arumugam, R Auld, H Aussel, T Babbedge, A Blain, J Bock, A Boselli, V Buat, D Burgarella, N Castro-Rodriguez, A Cava, P Chanial, A Conley, L Conversi, A Cooray, CD Dowell, E Dwek, S Eales, D Elbaz, M Fox, A Franceschini, W Gear, E Giovannoli, J Glenn, M Griffin, M Halpern, E Hatziminaoglou, E Ibar, K Isaak, RJ Ivison, G Lagache, L Levenson, N Lu, S Madden, B Maffei, G Mainetti, L Marchetti, G Marsden, AMJ Mortier, HT Nguyen, B O'Halloran, SJ Oliver, A Omont, MJ Page, P Panuzzo, A Papageorgiou, I Perez-Fournon, M Pohlen, N Rangwala, JI Rawlings, G Raymond, D Rigopoulou, D Rizzo, IG Roseboom, M Rowan-Robinson, MS Portal, D Scott, N Seymour, DL Shupe, AJ Smith, JA Stevens, M Symeonidis, M Trichas, KE Tugwell, M Vaccari, E Valiante, I Valtchanov, L Vigroux, L Wang, R Ward, G Wright, CK Xu, M Zemcov


HerMES: Halo occupation number and bias properties of dusty galaxies from angular clustering measurements

Astronomy and Astrophysics 518 (2010)

A Cooray, A Amblard, L Wang, V Arumugam, R Auld, H Aussel, T Babbedge, A Blain, J Bock, A Boselli, V Buat, D Burgarella, N Castro-Rodriguez, A Cava, P Chanial, DL Clements, A Conley, L Conversi, CD Dowell, E Dwek, S Eales, D Elbaz, D Farrah, M Fox, A Franceschini, W Gear, J Glenn, M Griffin, M Halpern, E Hatziminaoglou, E Ibar, K Isaak, RJ Ivison, AA Khostovan, G Lagache, L Levenson, N Lu, S Madden, B Maffei, G Mainetti, L Marchetti, G Marsden, K Mitchell-Wynne, AMJ Mortier, HT Nguyen, B O'Halloran, SJ Oliver, A Omont, MJ Page, P Panuzzo, A Papageorgiou, CP Pearson, I Perez Fournon, M Pohlen, JI Rawlings, G Raymond, D Rigopoulou, D Rizzo, IG Roseboom, M Rowan-Robinson, B Schulz, D Scott, P Serra, N Seymour, DL Shupe, AJ Smith, JA Stevens, M Symeonidis, M Trichas, KE Tugwell, M Vaccari, I Valtchanov, JD Vieira, L Vigroux, R Ward, G Wright, CK Xu, M Zemcov

We measure the angular correlation function, w(θ), from 0.5 to 30 arcmin of detected sources in two wide fields of the Herschel Multi-tiered Extragalactic Survey (HerMES). Our measurements are consistent with the expected clustering shape from a population of sources that trace the dark matter density field, including non-linear clustering at arcminute angular scales arising from multiple sources that occupy the same dark matter halos. By making use of the halo model to connect the spatial clustering of sources to the dark matter halo distribution, we estimate source bias and halo occupation number for dusty sub-mm galaxies at z ∼ 2. We find that sub-mm galaxies with 250 μm flux densities above 30 mJy reside in dark matter halos with mass above (5±4)×10 12 M ⊙ , while (14±8)% of such sources appear as satellites in more massive halos. © ESO 2010.


HerMES: The SPIRE confusion limit

Astronomy and Astrophysics 518 (2010)

HT Nguyen, B Schulz, L Levenson, A Amblard, V Arumugam, H Aussel, T Babbedge, A Blain, J Bock, A Boselli, V Buat, N Castro-Rodriguez, A Cava, P Chanial, E Chapin, DL Clements, A Conley, L Conversi, A Cooray, CD Dowell, E Dwek, S Eales, D Elbaz, M Fox, A Franceschini, W Gear, J Glenn, M Griffin, M Halpern, E Hatziminaoglou, E Ibar, K Isaak, RJ Ivison, G Lagache, N Lu, S Madden, B Maffei, G Mainetti, L Marchetti, G Marsden, J Marshall, B O'Halloran, SJ Oliver, A Omont, MJ Page, P Panuzzo, A Papageorgiou, CP Pearson, I Perez Fournon, M Pohlen, N Rangwala, D Rigopoulou, D Rizzo, IG Roseboom, M Rowan-Robinson, D Scott, N Seymour, DL Shupe, AJ Smith, JA Stevens, M Symeonidis, M Trichas, KE Tugwell, M Vaccari, I Valtchanov, L Vigroux, L Wang, R Ward, D Wiebe, G Wright, CK Xu, M Zemcov

We report on the sensitivity of SPIRE photometers on the Herschel Space Observatory. Specifically, we measure the confusion noise from observations taken during the science demonstration phase of the Herschel Multi-tiered Extragalactic Survey. Confusion noise is defined to be the spatial variation of the sky intensity in the limit of infinite integration time, and is found to be consistent among the different fields in our survey at the level of 5.8, 6.3 and 6.8 mJy/beam at 250, 350 and 500 μm, respectively. These results, together with the measured instrument noise, may be used to estimate the integration time required for confusion limited maps, and provide a noise estimate for maps obtained by SPIRE. © 2010 ESO.


HerMES: SPIRE galaxy number counts at 250, 350, and 500 μ m

Astronomy and Astrophysics 518 (2010)

SJ Oliver, L Wang, AJ Smith, B Altieri, A Amblard, V Arumugam, R Auld, H Aussel, T Babbedge, A Blain, J Bock, A Boselli, V Buat, D Burgarella, N Castro-Rodríguez, A Cava, P Chanial, DL Clements, A Conley, L Conversi, A Cooray, CD Dowell, E Dwek, S Eales, D Elbaz, M Fox, A Franceschini, W Gear, J Glenn, M Griffin, M Halpern, E Hatziminaoglou, E Ibar, K Isaak, RJ Ivison, G Lagache, L Levenson, N Lu, S Madden, B Maffei, G Mainetti, L Marchetti, K Mitchell-Wynne, AMJ Mortier, HT Nguyen, B O'Halloran, A Omont, MJ Page, P Panuzzo, A Papageorgiou, CP Pearson, I Pérez-Fournon, M Pohlen, JI Rawlings, G Raymond, D Rigopoulou, D Rizzo, IG Roseboom, M Rowan-Robinson, M Sánchez Portal, R Savage, B Schulz, D Scott, N Seymour, DL Shupe, JA Stevens, M Symeonidis, M Trichas, KE Tugwell, M Vaccari, E Valiante, I Valtchanov, JD Vieira, L Vigroux, R Ward, G Wright, CK Xu, M Zemcov


Cold dust and young starbursts: Spectral energy distributions of Herschel SPIRE sources from the HerMES survey

Monthly Notices of the Royal Astronomical Society 409 (2010) 2-11

M Rowan-Robinson, IG Roseboom, M Vaccari, A Amblard, V Arumugam, R Auld, H Aussel, T Babbedge, A Blain, J Bock, A Boselli, D Brisbin, V Buat, D Burgarella, N Castro-Rodriguez, A Cava, P Chanial, DL Clements, A Conley, L Conversi, A Cooray, CD Dowell, E Dwek, S Dye, S Eales, D Elbaz, D Farrah, M Fox, A Franceschini, W Gear, J Glenn, EAG Solares, M Griffin, M Halpern, E Hatziminaoglou, J Huang, E Ibar, K Isaak, RJ Ivison, G Lagache, L Levenson, N Lu, S Madden, B Maffei, G Mainetti, L Marchetti, AMJ Mortier, HT Nguyen, B O'Halloran, SJ Oliver, A Omont, MJ Page, P Panuzzo, A Papageorgiou, H Patel, CP Pearson, IP Fournon, M Pohlen, JI Rawlings, G Raymond, D Rigopoulou, D Rizzo, B Schulz, D Scott, N Seymour, DL Shupe, AJ Smith, JA Stevens, M Symeonidis, M Trichas, KE Tugwell, I Valtchanov, L Vigroux, L Wang, R Ward, G Wright, CK Xu, M Zemcov

We present spectral energy distributions (SEDs) for 68 Herschel sources detected at 5σ at 250, 350 and 500 μm in the HerMES SWIRE-Lockman field. We explore whether existing models for starbursts, quiescent star-forming galaxies and active galactic nucleus dust tori are able to model the full range of SEDs measured with Herschel. We find that while many galaxies ( 56 per cent) are well fitted with the templates used to fit IRAS, Infrared Space Observatory (ISO) and Spitzer sources, for about half the galaxies two new templates are required: quiescent ('cirrus') models with colder (10-20 K) dust and a young starburst model with higher optical depth than Arp 220. Predictions of submillimetre fluxes based on model fits to 4.5-24 μm data agree rather poorly with the observed fluxes, but the agreement is better for fits to 4.5-70 μm data. Herschel galaxies detected at 500 μm tend to be those with the highest dust masses. © 2010 The Authors. Journal compilation © 2010 RAS.


The Herschel Multi-Tiered Extragalactic Survey: Source extraction and cross-identifications in confusion-dominated SPIRE images

Monthly Notices of the Royal Astronomical Society 409 (2010) 48-65

IG Roseboom, SJ Oliver, M Kunz, B Altieri, A Amblard, V Arumugam, R Auld, H Aussel, T Babbedge, M Béthermin, A Blain, J Bock, A Boselli, D Brisbin, V Buat, D Burgarella, N Castro-Rodríguez, A Cava, P Chanial, E Chapin, DL Clements, A Conley, L Conversi, A Cooray, CD Dowell, E Dwek, S Dye, S Eales, D Elbaz, D Farrah, M Fox, A Franceschini, W Gear, J Glenn, EAG Solares, M Griffin, M Halpern, M Harwit, E Hatziminaoglou, J Huang, E Ibar, K Isaak, RJ Ivison, G Lagache, L Levenson, N Lu, S Madden, B Maffei, G Mainetti, L Marchetti, G Marsden, AMJ Mortier, HT Nguyen, B O'Halloran, A Omont, MJ Page, P Panuzzo, A Papageorgiou, H Patel, CP Pearson, I Pérez-Fournon, M Pohlen, JI Rawlings, G Raymond, D Rigopoulou, D Rizzo, M Rowan-Robinson, MS Portal, B Schulz, D Scott, N Seymour, DL Shupe, AJ Smith, JA Stevens, M Symeonidis, M Trichas, KE Tugwell, M Vaccari, I Valtchanov, JD Vieira, L Vigroux, L Wang, R Ward, G Wright, CK Xu, M Zemcov

We present the cross-identification and source photometry techniques used to process Herschel SPIRE imaging taken as part of the Herschel Multi-Tiered Extragalactic Survey (HerMES). Cross-identifications are performed in map-space so as to minimize source-blending effects. We make use of a combination of linear inversion and model selection techniques to produce reliable cross-identification catalogues based on Spitzer MIPS 24-μm source positions. Testing on simulations and real Herschel observations shows that this approach gives robust results for even the faintest sources (S 250 ~ 10 mJy). We apply our new technique to HerMES SPIRE observations taken as part of the science demonstration phase of Herschel. For our real SPIRE observations, we show that, for bright unconfused sources, our flux density estimates are in good agreement with those produced via more traditional point source detection methods (SUSSEXtractor) by Smith et al. When compared to the measured number density of sources in the SPIRE bands, we show that our method allows the recovery of a larger fraction of faint sources than these traditional methods. However, this completeness is heavily dependent on the relative depth of the existing 24-μm catalogues and SPIRE imaging. Using our deepest multiwavelength data set in the GOODS-N, we estimate that the use of shallow 24-μm catalogues in our other fields introduces an incompleteness at faint levels of between 20-40 per cent at 250 μm. © 2010 The Authors. Journal compilation © 2010 RAS.


Evolution of dust temperature of galaxies through cosmic time as seen by Herschel

Monthly Notices of the Royal Astronomical Society 409 (2010) 75-82

HS Hwang, D Elbaz, G Magdis, E Daddi, M Symeonidis, B Altieri, A Amblard, P Andreani, V Arumugam, R Auld, H Aussel, T Babbedge, S Berta, A Blain, J Bock, A Bongiovanni, A Boselli, V Buat, D Burgarella, N Castro-Rodríguez, A Cava, J Cepa, P Chanial, E Chapin, RR Chary, A Cimatti, DLZ Clements, A Conley, L Conversi, A Cooray, H Dannerbauer, M Dickinson, H Dominguez, CD Dowell, JS Dunlop, E Dwek, S Eales, D Farrah, NF Schreiber, M Fox, A Franceschini, W Gear, R Genzel, J Glenn, M Griffin, C Gruppioni, M Halpern, E Hatziminaoglou, E Ibar, K Isaak, RJ Ivison, WS Jeong, G Lagache, D Le Borgne, E Le Floc'h, HM Lee, JC Lee, MG Lee, L Levenson, N Lu, D Lutz, S Madden, B Maffei, B Magnelli, G Mainetti, R Maiolino, L Marchetti, AMJ Mortier, HT Nguyen, R Nordon, B O'Halloran, K Okumura, SJ Oliver, A Omont, MJ Page, P Panuzzo, A Papageorgiou, CP Pearson, I Pérez-Fournon, AMP García, A Poglitsch, M Pohlen, P Popesso, F Pozzi, JI Rawlings, D Rigopoulou, L Riguccini, D Rizzo, G Rodighiero, IG Roseboom, M Rowan-Robinson, A Saintonge, MS Portal, P Santini, M Sauvage, B Schulz, D Scott, N Seymour, L Shao, DL Shupe

We study the dust properties of galaxies in the redshift range 0.1 ≲z≲ 2.8 observed by the Herschel Space Observatory in the field of the Great Observatories Origins Deep Survey-North as part of the PACS Extragalactic Probe (PEP) and Herschel Multi-tiered Extragalactic Survey (HerMES) key programmes. Infrared (IR) luminosity (L IR ) and dust temperature (T dust ) of galaxies are derived from the spectral energy distribution fit of the far-IR (FIR) flux densities obtained with the PACS and SPIRE instruments onboard Herschel. As a reference sample, we also obtain IR luminosities and dust temperatures of local galaxies at z < 0.1 using AKARI and IRAS data in the field of the Sloan Digital Sky Survey. We compare the L IR -T dust relation between the two samples and find that the median T dust of Herschel-selected galaxies at z< 0.5 with L IR ≲ 5 × 10 10 L · appears to be 2-5 K colder than that of AKARI-selected local galaxies with similar luminosities, and the dispersion in T dust for high-z galaxies increases with L IR due to the existence of cold galaxies that are not seen among local galaxies. We show that this large dispersion of the L IR -T dust relation can bridge the gap between local star-forming galaxies and high-z submillimetre galaxies (SMGs). We also find that three SMGs with very low T dust (≲20 K) covered in this study have close neighbouring sources with similar 24-μm brightness, which could lead to an overestimation of FIR/(sub)millimetre fluxes of the SMGs. © 2010 The Authors. Journal compilation © 2010 RAS.


On the stellar masses of IRAC detected Lyman Break Galaxies at z ∼ 3

Monthly Notices of the Royal Astronomical Society 401 (2010) 1521-1531

GE Magdis, D Rigopoulou, JS Huang, GG Fazio

We present results of a large survey of the mid-infrared (mid-IR) properties of 248 Lyman Break Galaxies (LBGs) with confirmed spectroscopic redshift using deep Spitzer/Infrared Array Camera (IRAC) observations in six cosmological fields. By combining the new mid-IR photometry with optical and near-infrared observations, we model the spectral energy distributions (SEDs) employing a revised version of the Bruzual and Charlot synthesis population code that incorporates a new treatment of the thermal-pulsating asymptotic giant branch phase (CB07). Our primary aim is to investigate the impact of the AGB phase in the stellar masses of the LBGs, and compare our new results with previous stellar mass estimates. We investigate the stellar mass of the LBG population as a whole and assess the benefits of adding longer wavelengths to estimates of stellar masses for high-redshift galaxies. Based on the new CB07 code, we find that the stellar masses of LBGs are smaller on an average by a factor of ∼1.4 compared to previous estimates. LBGs with 8 and/or 24 μm detections show higher masses (M* ∼ 1011 M ⊙) than LBGs faint in the IRAC bands (M* ∼ 109 M⊙). The ages of these massive LBGs are considerably higher than the rest of the population, indicating that they have been star forming for at least ∼1 Gyr. We also show how the addition of the IRAC bands improves the accuracy of the estimated stellar masses and reduced the scatter on the derived mass-to-light ratios. In particular, we present a tight correlation between the 8 μm IRAC band (rest-frame K for galaxies at z ∼ 3) and the stellar mass. We calculate the number density of massive (M * > 1011 M⊙) LBGs and find it to be Φ = (1.12 ± 0.4) × 10-5 Mpc-3, ∼1.5 times lower than that found by previous studies. Finally, based on ultraviolet-corrected star formation rates (SFRs), we investigate the SFR-stellar mass correlation at z ∼ 3, find it similar to the one observed at other redshifts and show that our data place the peak of the evolution of the specific SFR at z ∼ 3. © 2009 RAS.


Measures of star formation rates from infrared (Herschel) and UV (GALEX) emissions of galaxies in the HerMES fields

Monthly Notices of the Royal Astronomical Society: Letters 409 (2010)

V Buat, E Giovannoli, D Burgarella, B Altieri, A Amblard, V Arumugam, H Aussel, T Babbedge, A Blain, J Bock, A Boselli, N Castro-Rodríguez, A Cava, P Chanial, DL Clements, A Conley, L Conversi, A Cooray, CD Dowell, E Dwek, S Eales, D Elbaz, M Fox, A Franceschini, W Gear, J Glenn, M Griffin, M Halpern, E Hatziminaoglou, S Heinis, E Ibar, K Isaak, RJ Ivison, G Lagache, L Levenson, CJ Lonsdale, N Lu, S Madden, B Maffei, G Magdis, G Mainetti, L Marchetti, GE Morrison, HT Nguyen, B O'Halloran, SJ Oliver, AA Omont, FN Owen, MJ Page, M Pannella, P Panuzzo, A Papageorgiou, CP Pearson, I Pérez-Fournon, M Pohlen, D Rigopoulou, D Rizzo, IG Roseboom, M Rowan-Robinson, M Sánchez Portal, B Schulz, N Seymour, DL Shupe, AJ Smith, JA Stevens, V Strazzullo, M Symeonidis, M Trichas, KE Tugwell, M Vaccari, E Valiante, I Valtchanov, L Vigroux, L Wang, R Ward, G Wright, CK Xu, M Zemcov

The reliability of infrared (IR) and ultraviolet (UV) emissions to measure star formation rates (SFRs) in galaxies is investigated for a large sample of galaxies observed with the Spectral and Photometric Imaging Receiver (SPIRE) and the Photodetector Array Camera and Spectrometer (PACS) instruments on Herschel as part of the Herschel Multi-Tiered Extragalactic Survey (HerMES) project. We build flux-limited 250-jj.m samples of sources at redshift z < 1, crossmatched with the Spitzer/MIPS and GALEX catalogues. About 60 per cent of the Herschel sources are detected in UV. The total IR luminosities, LIR, of the sources are estimated using a spectral energy distribution (SED) fitting code that fits to fluxes between 24 and 500 μm. Dust attenuation is discussed on the basis of commonly used diagnostics: the LIR/LUV ratio and the slope, β, of the UV continuum. A mean dust attenuation AUV of ≃3 mag is measured in the samples. LIR/LUV LIR. Galaxies with LIR > 1011 L⊙ and 0.5 < z < 1 exhibit a mean dust attenuation AUV of about 0.7 mag lower than that found for their local counterparts, although with a large dispersion. Our galaxy samples span a large range of β and LIR/LUV values which, for the most part, are distributed between the ranges defined by the relations found locally for starburst and normal star-forming galaxies. As a consequence the recipe commonly applied to local starbursts is found to overestimate the dust attenuation correction in our galaxy sample by a factor of ~2-3. The SFRs deduced from LIR are found to account for about 90 per cent of the total SFR; this percentage drops to 71 per cent for galaxies with SFR < 1 M⊙ yr-1 (or LIR < 1010L⊙). For these faint objects, one needs to combine UV and IR emissions to obtain an accurate measure of the SFR. © 2010 The Authors. Journal compilation © 2010 RAS.


HerMES: Herschel-SPIRE observations of Lyman break galaxies

Monthly Notices of the Royal Astronomical Society: Letters 409 (2010)

D Rigopoulou, G Magdis, RJ Ivison, A Amblard, V Arumugam, H Aussel, A Blain, J Bock, A Boselli, V Buat, D Burgarella, N Castro-Rodríguez, A Cava, P Chanial, DL Clements, A Conley, L Conversi, A Cooray, CD Dowell, E Dwek, S Eales, D Elbaz, D Farrah, A Franceschini, J Glenn, M Griffin, M Halpern, E Hatziminaoglou, JS Huang, E Ibar, K Isaak, G Lagache, L Levenson, N Lu, S Madden, B Maffei, G Mainetti, L Marchetti, HT Nguyen, B O'Halloran, SJ Oliver, A Omont, MJ Page, P Panuzzo, A Papageorgiou, CP Pearson, I Pérez-Fournon, M Pohlen, D Rizzo, IG Roseboom, M Rowan-Robinson, B Schulz, D Scott, N Seymour, DL Shupe, AJ Smith, JA Stevens, M Symeonidis, M Trichas, KE Tugwell, M Vaccari, I Valtchanov, L Vigroux, L Wang, G Wright, CK Xu, M Zemcov

We present first results of a study of the submillimetre (submm) (rest-frame far-infrared) properties of z ~ 3 Lyman break galaxies (LBGs) and their lower redshift counterparts BX/BM galaxies, based on Herschel-SPIRE observations of the Northern field of the Great Observatories Origins Deep Survey (GOODS-N). We use stacking analysis to determine the properties of LBGs well below the current limit of the survey. Although LBGs are not detected individually, stacking the infrared luminous LBGs (those detected with Spitzer at 24 |xm) yields a statistically significant submm detection with mean flux 〈S 250 〉 = 5.9 ±1.4 mJy confirming the power of SPIRE in detecting UV-selected high-redshift galaxies at submm wavelengths. In comparison, the Spitzer 24 |j.m detected BX/BM galaxies appear fainter with a stacked value of 〈S 250 〉 = 2.7 ± 0.8 mJy. By fitting the spectral energy distributions (SEDs) we derive median infrared luminosities, L IR , of 2.8 × 10 12 L ⊙ and 1.5 × 10 11 L. for z ~ 3 LBGs and BX/BMs, respectively. We find that LIR estimates derived from present measurements are in good agreement with those based on UV data for z ~ 2 BX/BM galaxies, unlike the case for z ~ 3 infrared luminous LBGs where the UV underestimates the true LIR. Although sample selection effects may influence this result we suggest that differences in physical properties (such as morphologies, dust distribution and extent of star-forming regions) between z ~ 3 LBGs and z ~ 2 BX/BMs may also play a significant role. © 2010 The Authors. Journal compilation © 2010 RAS.


HerMES: SPIRE detection of high-redshift massive compact galaxies in GOODS-N field

Monthly Notices of the Royal Astronomical Society: Letters 409 (2010)

A Cava, G Rodighiero, I Pérez-Fournon, F Buitrago, I Trujillo, B Altieri, A Amblard, R Auld, J Bock, D Brisbin, D Burgarella, N Castro-Rodríguez, P Chanial, M Cirasuolo, DL Clements, CJ Conselice, A Cooray, S Eales, D Elbaz, P Ferrero, A Franceschini, J Glenn, EG González Solares, M Griffin, E Ibar, RJ Ivison, L Marchetti, GE Morrison, AMJ Mortier, SJ Oliver, MJ Page, A Papageorgiou, CP Pearson, M Pohlen, JI Rawlings, G Raymond, D Rigopoulou, IG Roseboom, M Rowan-Robinson, D Scott, N Seymour, AJ Smith, M Symeonidis, KE Tugwell, M Vaccari, I Valtchanov, JD Vieira, L Vigroux, L Wang, G Wright

Wehave analysed the rest-frame far-infrared properties ofa sample of massive (M * > 10 11 M ⊙ ) galaxies at 2 ≲ z ≲ 3 in the Great Observatories Origins Deep Survey-North (GOODS-N) field using the Spectral and Photometric Imaging Receiver (SPIRE) instrument aboard the Herschel Space Observatory. To conduct this analysis we take advantage of the data from the Herschel Multi-tiered Extragalactic Survey (HerMES) key programme. The sample comprises 45 massive galaxies with structural parameters characterized with HST NICMOS-3. We study detections at submm Herschel bands, together with Spitzer 24-μm data, as a function of the morphological type, mass and size. We find that 26/45 sources are detected at MIPS 24 μm and 15/45 (all MIPS 24-μm detections) are detected at SPIRE 250 μ with disc-like galaxies more easily detected. We derive star formation rates (SFRs) and specific star formation rates (sSFRs) by fitting the spectral energy distribution of our sources, taking into account non-detections for SPIRE and systematic effects for MIPS derived quantities. We find that the mean SFR for the spheroidal galaxies (~50-100M ⊙ yr -1 ) is substantially (a factor ~3) lower than the mean value presented by disc-like galaxies (~250-300M ⊙ yr -1 ). © 2010 The Authors. Journal compilation © 2010 RAS.


Herschel reveals a T <inf>dust</inf> -unbiased selection of z~ 2 ultraluminous infrared galaxies

Monthly Notices of the Royal Astronomical Society 409 (2010) 22-28

GE Magdis, D Elbaz, HS Hwang, A Amblard, V Arumugam, H Aussel, A Blain, J Bock, A Boselli, V Buat, N Castro-Rodríguez, A Cava, P Chanial, DL Clements, A Conley, L Conversi, A Cooray, CD Dowell, E Dwek, S Eales, D Farrah, A Franceschini, J Glenn, M Griffin, M Halpern, E Hatziminaoglou, J Huang, E Ibar, K Isaak, E Le Floc'h, G Lagache, L Levenson, CJ Lonsdale, N Lu, S Madden, B Maffei, G Mainetti, L Marchetti, GE Morrison, HT Nguyen, B O'Halloran, SJ Oliver, A Omont, FN Owen, MJ Page, M Pannella, P Panuzzo, A Papageorgiou, CP Pearson, I Pérez-Fournon, M Pohlen, D Rigopoulou, D Rizzo, IG Roseboom, M Rowan-Robinson, B Schulz, D Scott, N Seymour, DL Shupe, AJ Smith, JA Stevens, V Strazzullo, M Symeonidis, M Trichas, KE Tugwell, M Vaccari, I Valtchanov, L Vigroux, L Wang, G Wright, CK Xu, M Zemcov

Using Herschel Photodetector Array Camera (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) observations of Lockman Hole-North and Great Observatories Origins Deep Survey-North (GOODS-N) as part of the Herschel Multi-tiered Extragalactic Survey (HerMES) project, we explore the far-infrared (IR) properties of a sample of mid-IR-selected starburst-dominated ultraluminous infrared galaxies (ULIRGs) at z~ 2. The selection of the sample is based on the detection of the stellar bump that appears in the spectral energy distribution of star-forming galaxies at 1.6 μm. We derive robust estimates of infrared luminosities (L IR ) and dust temperatures (T d ) of the population and find that while the luminosities in our sample span less than an order of magnitude (12.24 ≤ log(L IR /L · ) ≤ 12.94), they cover a wide range of dust temperatures (25 ≤T d ≤ 62 K). Galaxies in our sample range from those that are as cold as high-z submillimetre galaxies (SMGs) to those that are as warm as optically faint radio galaxies (OFRGs) and local ULIRGs. Nevertheless, our sample has median T d = 42.3 K, filling the gap between SMGs and OFRGs, bridging the two populations. We demonstrate that a significant fraction of our sample would be missed from ground-based (sub)mm surveys (850-1200 μm), showing that the latter introduce a bias towards the detection of colder sources. We conclude that Herschel observations confirm the existence of high-z ULIRGs warmer than SMGs, show that the mid-IR selection of high-z ULIRGs is not T d dependent, reveal a large dispersion in T d of high-z ULIRGs and provide the means to characterize the bulk of the ULIRG population, free from selection biases introduced by ground-based (sub)mm surveys. © 2010 The Authors. Journal compilation © 2010 RAS.


Spectral energy distributions of type 2 quasi-stellar objects: Obscured star formation at high redshifts

Monthly Notices of the Royal Astronomical Society 400 (2009) 1199-1207

D Rigopoulou, V Mainieri, O Almaini, A Alonso-Herrero, JS Huang, G Hasinger, G Rieke, J Dunlop, I Lehmann

We present new mid-infrared and submillimetre observations for a sample of eight high-redshift type 2 quasi-stellar objects (QSOs) located in the Chandra Deep Field-South. The sources are X-ray absorbed with luminosities in excess of 1044 erg s-1. Two of the targets have robust detections, S/N > 4, while further three targets are marginally detected with S/N ≥ 2.5. All sources are detected in multiple mid-infrared bands with the Spitzer Space Telescope. The multiwavelength spectral energy distributions (SEDs) of the type 2 QSOs are compared to those of two local ultraluminous galaxies (Arp220 and IR22491) in order to assess contributions from a star-forming component in various parts of the SED. We suggest that their submm emission is possibly due to a starburst while a large fraction of the mid-infrared energy is likely to originate in the obscured central quasar. Using the mid-infrared and submm observations, we derive infrared luminosities which are found to be in excess of L > 1012 L⊙. The submm (850 μm) to X-ray (2 keV) spectral indices (αSX) span a wide range. About half of the type 2 QSOs have values typical for a Compton-thick active galactic nuclei with only 1 per cent of the nuclear emission seen through scattering, and the remaining with values typical of submm-bright galaxies. Combining the available observational evidence, we outline a possible scenario for the early stages of evolution of these sources. © 2009 RAS.

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